Brycinus
Brycinus Valenciennes, 1850
Adipose eyelid rudimentary, hardly visible; swim bladder not prolonged beyond anus into caudal peduncle. The species in this genus can be arranged into three groups:
Synonyms
Myletes Cuvier, 1814 (partim)
Chalceus Cuvier, 1818 (partim)
Alestes Müller & Troschel, 1844 (partim)
Brachyalestes Günther, 1864
Micralestes Boulenger, 1899 (partim)
Type species: Brycinus macrolepidotus
Brycinus macrolepidotus Valenciennes, 1850 by monotypy.
Currently, 36 species are assigned to the genus Brycinus.
Key to species
1 Fronto-parietal fontanel narrow but always present................................................................2
Fronto-parietal fontanel absent in adults, sometimes pore-like in juvelines.............................12
2 6 teeth in the outer premaxillary row....................................................................................3
8-12 teeth in the outer premaxillary row...............................................................................9
3 16-19 gill rakers on lower limb (ceratobranchial) of first gill arch.............................................4
12-15 gill rakers on lower limb (ceratobranchial) of first gill arch.............................................5
4 Gill rakers short...............................................................................................B. leuciscus
Gill rakers long.....................................................................................................B. luteus
5 5½ scales in transverse row between lateral line and dorsal fin origin.....................................6
6½ scales in transverse row between lateral line and dorsal fin origin.....................................8
6 13 predorsal scales.............................................................................................B. bartoni
8½-11½ predorsal scales...................................................................................................7
7 Precaudal spot elongate, extending to end of caudal fin...................................B. longipinnis
Precaudal spot ovoid, not extending unto caudal fin rays......................................B. derhami
8 19-21 branched anal fin rays; 31-34 scales along lateral line; no humeral spot...B. intermedius
22-25 branched anal fin rays; 34-38 scales along lateral line; humeral spot present.B. tholloni
9 4½ scales in transverse row between lateral line and dorsal fin origin......................B. humilis
5½-6½ scales in transverse row between lateral line and dorsal fin origin.............................10
10 16-17 short gill rakers on lower limb (ceratobranchial) of first gill arch................B. tessmanni
18-22 long gill rakers on lower limb (ceratobranchial) of first gill arch...................................11
11 11-11½ predorsal scales; rayed dorsal fin origin at about the same level as pelvic fin insertion.
......................................................................................................................B. lateralis
12½-14 predorsal scales; rayed dorsal fin origin distinctly behind pelvic fin insertion.................
........................................................................................................................B. sadleri
12 Snout short, more than three times head length; rayed dorsal fin origin at same level as, or
justbehind, pelvic fin insertion; head narrow; adults medium-sized; sexual dimorphism affec-
ting anal fin shape........................................................................................................13
Snout long, less than three times head length; rayed dorsal fin origin distinctly behind pel-
vic fin insertion; head large; adults large-sized; no sexual dimorphism affecting anal fin shape
....................................................................................................................................29
13 Humeral spot absent....................................................................................................14
Humeral spot present....................................................................................................15
14 12 branched anal fin rays; 19 gill rakers on lower limb (ceratobranchial) of first gill arch; flanks
without dark lateral band.......................................................................................B. abeli
15-17 branched anal fin rays; 25-28 gill rakers on lower limb (ceratobranchial) of first gill arch;
a distinct black lateral stripe extending from middle of rayed dorsal to the caudal fin................
....................................................................................................................B. taeniurus
15 Longitunal black stripe or black spots on sides...............................................................16
No trace of striping or spotting on sides...........................................................................20
16 An oval black spot on the sides behind rayed dorsal fin insertion...................B. bimaculatus
A black stripe (total or partial) on the sides......................................................................17
17 A black stripe all along the sides....................................................................................18
A black lateral stripe extending from the rayed dorsal insertion to the caudal fin..................21
18 Head width 2.0-2.2 in its length; greatest depth 3.4-4.2 in the standard length; outer premaxil-
lary teeth monoserial; an black longitunal stripe on sides, slightly marked in front of the rayed
dorsal fin................................................................................................ B. opisthotaenia
Head width 1.6-1.9 in its length; greatest depth 1.7-3.0 in the standard length; outer premaxil-
lary teeth biserial; an uniform black longitunal stripe on sides............................................19
19 24-26 scales along lateral line; 20-21 gill rakers on lower limb (ceratobranchial) of first gill arch;
upper Niger basin............................................................................................B. carolinae
18-22 scales along lateral line; 13-17 gill rakers on lower limb (ceratobranchial) of first gill arch;
middle Congo basin.......................................................................................B. epuluensis
20 Pectoral fin insertion just below operculum; 29-31 scales along lateral line....... B. peringueyi
Pectoral fin insertion behind operculum; 26-28 scales along lateral line..............B. kingsleyae
21 4½ scales in transverse row between lateral line and dorsal fin origin.................................22
5½ scales in transverse row between lateral line and dorsal fin origin..................................25
22 Caudal fin broadly black edged.....................................................................B. nigricauda
Caudal fin not black edged.............................................................................................23
23 Black spot of the caudal peduncle continues as a longitudinal band to the tips of the middle
caudal rays.....................................................................................................B. comptus
Black spot of the caudal peduncle extends at most only half the length of the middle caudal
rays.............................................................................................................................24
24 Humeral spot close to operculum above the 3rd -4th scales of the lateral line..........B. imberi
Humeral spot above the 5th - 6th scales of the lateral line...................................B. fwaensis
25 Rayed dorsal fin origin behind pelvic fin insertion; 15-17 branched anal fin rays........B. affinis
Rayed dorsal fin origin at about the same level as pelvic fin insertion; 10-16 branched anal fin
rays.............................................................................................................................26
26 Sharply pointed fang-like teeth..............................................................................B. ferox
Teeth of the two jaws normally developed........................................................................27
27 Mouth superior; small-sized species.................................................................B. minutus
Mouth terminal; medium-sized species...........................................................................28
28 Snout length 2.8-3.6 in head length; caudal fin red; always 5½ scales in transverse row bet-
ween lateral line and dorsal fin origin.....................................................................B. nurse
Snout length 3.8-4.1 in head length; caudal fin orange; generally 5½ but sometimes 4½ scales
in transverse row between lateral line and dorsal fin origin...................................B. jacksonii
29 Large and well-developed interorbital space; 9-12 branched anal fin rays............................30
Thin and few-developed interorbital space; 11-16 branched anal fin rays..............................33
30 8-9 predorsal scales; 21-23 scales along lateral line.............................................B. poptae
10½-12 predorsal scales ; 24-29 scales along lateral line..................................................31
31 Body depth less than 3 times in standard length.......................................... B. carmesinus
Body depth more than 3.3 times in standard length..........................................................32
32 Fins colourless; two first branched anal fin rays very thick; dark stripe absent on flanks; 2½
transverse scales below lateral line..........................................................B. grandisquamis
Fins greyish black edged; branched anal fin rays normally developed; generally a broad dark
stripe on flanks; 3½ transverse scales below lateral line.................................B. schoutedeni
33 2½ transverse scales below lateral line; 12½-13½ predorsal scales...............B. rhodopleura
3½ transverse scales below lateral line; 9½-12 predorsal scales........................................34
34 Body depth less than 3 times in standard length....................................................B. brevis
Body depth more than 3 times in standard length.............................................................35
35 21-28 scales along lateral line; upper jaw longer than lower jaw in adult.....B. macrolepidotus
29-31 scales along lateral line; upper jaw no much than lower jaw in adult...............B. batesii
Types and type localities
Alestes abeli Joannis, 1835: 225, fig. 8. Type locality: “Fort Sibut, Ubangi-Shari”. Holotype: ANSP 65545. Paratypes:65546-65547, 65548 (c&s).
Synonyms
Alestes abeli Fowler, 1936
Alestopetersius (Alestogrammus) abeli Hoedeman, 1951
Phenacogrammus (Alestogrammus) abeli Hoedeman, 1959
Brycinus abeli Géry, 1968
Common names
Estonian: Abeli kardsalmler
Description
Diagnosis: measurements and counts of the original description and those of the types revised are given below.
Brycinus abeli: main morphological characters of types.
The two type specimens examined have a narrow fronto-parietal fontanel. The adipose eyelid is rudimentary. The lower jaw is prominent. The humeral spot is absent but it exists a broad band on the caudal peduncle extending backwards on median caudal-fin rays.
Supplementary description by Géry, 1995: “Brycinus abeli has a bluntly pointed head with a flat top, the mouth supero-terminal with a prominent mandible, a low scale count (4-4½/27/1½-2), a short anal fin (iii,11-12), only three external premaxillary teeth on each side, and fairly numerous gill-rakers (20- 22 on the lower arch). Paugy (1986), who was able to examine two of the types, says that this species "resembles B. imberi), but without a humeral spot". This is corroborated by the absence of a fontane! in the present specimens (as in adult or semi-adult B. imberi)), whereas the types, presumably juveniles, have, according to Paugy (loc. cit.), a fronto-parietal fontane!. Greatest depth about 3.0 and length of head about 3.4 in SL; interorbital width about 2.55 in the length of head; dorsal fin origin clearly behind mid body and behind pelvic fin level; caudal peduncle shorter than that figured by Fowler (1936), its depthonly about 1.2 in its length. A large, conspicuous, oval caudal spot, not reaching to end of fin; no humeral spot.”
Maximum reported size: 58 mm SL.
Colour: according to Fowler: “Pale brownish, lower surfaces paler, evidently whitish in life. (...) Fins otherwise all pale, only slightly greyish terminally. Some specimens with end of longest dorsal and anal rays dusky or even blackish. Iris grey.”
Affinities: close to B. imberi), but the humeral spot is absent in B. abeli (present in B. imberi)>).
Distribution
B. abeli is known from Ubangui River drainage (middle Congo River basin) in Central African Republic and Democratic Republic of the Congo (Géry, 1995) (see also Faunafri).
Brycinus abeli is only known from Fort Sibut, Ubangui River, Central Congo basin. Its taxonomic status needs to be verified. With exception of the humeral spot, Brycinus abeli resembles Brycinus imberi (Paugy 1986). More research is needed before an assessment can be made.
Major threats: none known.
Bibliography
Brycinus affinis (Günther, 1894)
Types and type localities
Alestes affinis Günther, 1894: 90. Type locality: “Merifano on the Tana River”, syntypes BMNH n° 1893.12.2:51-53..
Synonyms
Alestes affinis Günther, 1894
Alestes imberi (non Peters) Vinciguerra, 1895
Brachyalestes affinis Fowler, 1906
Brycinus affinis Myers, 1929
Common names
English: Redfin robber (Kenya)
Estonian: Punauim-kardsalmler
Finnish: Punaeväalesti
German: Rotfeder-Salmler
Pokomo: Nkwakwa (Kenya)
Swahili: Gingi/Kasa/Ngacha (Tanzania)
Description
Diagnosis: the integral Günther's original description is: “Allied to Alestes imberi. D.ll. A.18-19. L. lat. 21. L. transversal 5/3. The height of the body is one third of the total length (without caudal) ; the length of the head two sevenths. The origin of the dorsal fin is distinctly behind the base of the ventrals ; pectoral reaching the ventrals. Silvery, with an indistinct shining band along the side ; a blackish spot behind the shoulder an another at the root of the caudal. Three specimens, 3 1/2 inches long, were obtained at Merifano on the Tana River.”
Measurements and counts of types revised and from 5 Somalian specimens are given below:
Brycinus affinis: main morphological characters of types and additional material.
All small specimens examined have a very narrow fronto-parietal fontanel which is closed at 75 mm SL. The adipose eyelid is rudimentary. The longest rays of the pectoral fins extend beyond the insertion of the ventral fins. Ventral fins origin is distinctly before the dorsal fin insertion. Body with a humeral spot and a pale small spot on the caudal peduncle. The species presents a sexual dimorphism affecting the shape of the anal fin.
Maximum reported size: 147 mm SL.
Affinities: this species is close to B. nurse, but it has less anal fin branched rays and scales on the lateral line. Furthermore, B. affinis has a more developed supra-orbital bone. Dorsal-fin origin is distinctly behind the ventral-fins origin.
Reproduction
B. affinis undertake anadromous migrations during the reproduction season. Spawning takes place from April to June and spawning sites are chosen in running water zone with seeding bottom (Copley, 1958).
Diet
B. affinis feed with small fishes, aquatic insects (larvae and adults), snails and grass (Copley, 1958).
Distribution
East Africa (Eastern ichthyo-province): Pangani, Wami, Ruvu, Rufigi, Kilombero, Ruaha, Athi, Tana, Juba and Webi-Shebeli Rivers (see also Faunafri).
This species has a wide distribution, with no known major widespread threats. It is therefore listed as Least Concern. It has also been assessed regionally as Least Concern for eastern Africa, as although there are known threats from seine fishing, there is no indication of population decline. Due to a lack of information on this species distribution and threats, it has been assessed as Data Deficient for northeast Africa.
Major threats: threats to this species include fishing across rivers during the migration using illegal small mesh nets and other methods, siltation and land based pollution.
Bibliography
Brycinus bartoni (Nichols & La Monte, 1953)
Type and type locality
Alestes bartoni Nichols & La Monte, 1953: 1-2. Type locality: “Mouila, Ogowe Valley, Gaboon”, holotype AMNH n° 19654.
Synonyms
Alestes bartoni Nichols & La Monte, 1953
Brycinus bartoni Paugy, 1986
Common names
Estonian: Bartoni kardsalmler
Description
Diagnosis: fronto-parietal fontanel pore-like. A black humeral spot and a precaudal spot extending onto proximal portion of median rays of the caudal fin. Pronounced sexual dimorphism affecting the shape of anal fin in adult males. Adult males have dorsal fin rays filamentous. Like most of the species of this group, males are larger than females
Measurements and counts of the original description and those of the type revised are given below.
Brycinus bartoni: main morphological characters of types.
Maximum reported size: 92 mm SL (male) and 74 mm SL (female).
Colour: as all species of B. longipinnis group.
Affinities: B. bartoni is close to B. longipinnis. The two species are distinguished by predorsal scale counts (13 in B. bartoni vs 8½-11½ in B. longipinnis). It is also similar to B. intermedius and B. tholloni, but has fewer scales in transverse row between lateral line and dorsal fin origin (5½ vs 6½).
Distribution
Until recently this species was known only from the holotype from the Ogowe basin (Ngounié at Mouila). However, many specimens have since been collected from this left bank tributary of the Ogowe. The species appears to be endemic to this basin and is not found in upper courses of the Ogowe or in the Ivindo (see also Faunafri).
Brycinus bartoni is threatened by slash and burn agriculture and commercial logging (pers. comm. Victor Mamonekene). This species has a limited distribution though and is probably endemic to the lower Ogowe basin, occurring in fewer than five localities.
Brycinus bartoni is threatened by slash and burn agriculture and commercial logging (pers. comm. Victor Mamonekene).
Bibliography
Brycinus batesii (Boulenger, 1903)
Type and type locality:
Alestes batesii Boulenger, 1903: 435. Type locality: “Kribi River at Efulen”, syntypes BMNH n° 1902.11.12:110-111
Synonyms
Alestes batesii Boulenger, 1903
Alestes batesi Monod, 1928
Brycinus batesii Myers, 1929
Brycinus batesi Géry, 1968
Common names
Estonian: Batesi kardsalmler
Description
Diagnosis: the fronto-parietal fontanel is absent. The adipose eyelid is rudimentary. The supra-orbitary bone is moderately developed. As all the species of the B. macrolepidotus group, B. batesii has no sexual dimorphism affecting the anal fin shape.
Measurements and counts of the original description, those of the types revised and of one specimen from Cameroon are given below.
Brycinus batesii: main morphological characters of types and additional material (* total length).
Maximum reported size: 245 mm TL (male).
Colour: according to Boulenger (1903) “Olive brown above and on the sides, whitish beneath ; a large round black spot on the caudal peduncle, at the base of the caudal fin ; fins greyish ; or blackish at the end.”
Affinities: B. batesii is close to B. macrolepidotus but has more scales along the lateral line (29-31 vs 21-28). Moreover, in very large specimens the upper jaw does not exceed the lower jaw as in B. macrolepidotus.
Remarks: four species, with limited distribution, are very close to B. macrolepidotus: B. batesii (Cameroon), B. brevis (some coastal rivers in Ghana and Nigeria), B. rhoddopleura (Lake Tanganyika) and B. schoutedeni (South Cameroon to Congo). A study in progress indicates that these species have characters which exhibit a clinal geographic variation. Similar, clinal variation was already observed in West Africa (Paugy, 1982 b). In anticipation of the conclusions of the ongoing study, B. macrolepidotus is generally considered the only species of this group present in Africa.
Diet
B batesii lives on the surface and feeds on insects and leaves
Distribution
Coastal basins of Cameroon (see also Faunafri).
IUCN assessment
Not evaluated
Bibliography
Brycinus bimaculatus (Boulenger, 1899)
Type and type locality
Alestes bimaculatus Boulenger, 1899: 85. Type locality: “Kutu, Lac Leopold II”, syntypes BMNH n° 1899.9.26:92-93.
Synonyms
Alestes bimaculatus Boulenger, 1899
Brycinus bimaculatus Myers, 1929
Alestes curtus (non Boulenger) David & Poll, 1937
Alestobrycon taeniurus bimaculatus Hoedeman, 1951
Common names
Estonian: Kakstäpp-kardsalmler
Finnish: Kaksitäpläalesti
Description
Diagnosis: comparing the original description and our revision, we note a high difference between the numbers of gill rakers counted on the lower limb of the first arch (22-26 vs 29-31). In the original description Boulenger (1899) notes that gill rakers are long and thin. We have also observed this character. Counts of Boulenger are more or less similar to those we ourselves observed in the Congolese rivers. But, in these rivers, specimens have relative short and thick gill rakers. A difference of 3, or more, gill rakers could suggest two different species. However, in lakes, Alestes s.l. are often planktivorous filterers. In this way, it is possible that can appear an adaptation in the number and in the form of the gill rakers in the lake Maji Ndombe, the type locality. In smallest specimen observed (52 mm SL), a pore like fronto-parietal fontanel exists. In other specimens the fontanel has disappeared. The adipose eyelid is rudimentary. The supra-orbital bone is well developed. The humeral spot is absent but there are two other ovoid spot, the first on the lateral line slightly behind the dorsal-fin and the second on the caudal peduncle.
Measurements and counts of the original description, those of the types revised and of several specimens from the Congo River are given below.
Brycinus bimaculatus: main morphological characters of types and additional material (* total length).
Maximum reported size: 140 mm TL (male).
Colour: according to Boulenger (1899) “dark green above, silvery below; (…) fins are yellowish with sometimes the adipose orange. Iris of the eye is yellow or orange”. Matthes (1964) gives more precisions concerning live specimens: “back brown to greenish with coppered reflections; belly whitish; chin rust; scales of the flanks and sides of the head with green bronze and golden reflections (blue-green in juveniles). Sometimes, there is a brown band on the flanks. (…). Eye red-orange or coppered, yellow below with a black-green spot above and below. Vertical fins are red-rust, others are more or less orange".
Affinities: B. bimaculatus is close to B. imberi but differs by the coloration pattern. In B. bimaculatus humeral spot is absent (present in B. imberi) but there are two large ovoid spots on the flanks (a single spot on the caudal peduncle in B. imberi).
Reproduction
In Lake Tumba, all specimens are mature in August-September . Eggs are cream-coloured to pale yellow and measure 0.8 to 1.0 mm in diameter. In a female 127 mm long he counts 9,900 eggs (Matthes, 1964a).
Diet
In Lake Tumba, B. bimaculatus is omnivorous with an entomophagous preference. Stomach contents contained: sand, filamentous algae, grass, Ephemeroptera nymphs (Povilla) and insects remains among them a part of terrestrial origin. Young specimens eat also Cladocera and small insects (Matthes, 1964a).
Habitat
B. bimaculatus inhabits rivers as well as lakes particularly calm water of the edge.
Distribution
Upper and middle Congo basin, Lualaba, Rubi, lake Upemba and lake Tumba (see also Faunafri).
The species is widespread or without major threats throughout central Africa with no major threats, and is assessed as Least Concern.
Major threats: none known.
Bibliography
Brycinus brevis (Boulenger, 1903)
Type and type locality
Alestes brevis Boulenger, 1903: 594. Type locality: “Lagos”, syntypes BMNH n° 1903.4.24:154-155.
Synonyms
Alestes brevis Boulenger, 1903
Brycinus brevis Myers, 1929
Common names
English: African tetra (Cameroon), Characin/Silversides (Ghana)
Estonian: Särg-kardsalmler
Ewe: Dzogla dzevui (Ghana)
Ga: Tewe kpiti (Ghana)
German: Kleiner Großaugensalmler
Ijo: Elei (Nigeria)
Description
Diagnosis: body depth comprised less than three times in standard length. Supraorbital bone thick. Even in the largest specimens, snout projecting only slightly beyond lower jaw. Dorsal-fin origin at about midpoint of space between pelvic-fin insertions and anal-fin origin. Scale formula: 4½/21-23/2½-3½. Anal fin with three spines and 13-15 branched rays. Lower (ceratobranchial) limb of first gill arch with 18-20 gill rakers. This species shows a sexual dimorphism affecting the anal-fin shape in adult males. On the specimen examined, the fronto-parietal fontanel is absent. The adipose eyelid is rudimentary. The supra-orbital bone is thick. In large specimens, the snout weakly exceeds the lower jaw. All the ten teeth of the premaxillary are arranged on a single row.
Measurements and counts of the original description and those of one syntype revised are given below.
Brycinus brevis: main morphological characters of types (*total length).
Maximum reported size: 225 mm TL.
Colour: according to Boulenger (1903b) "uniform brownish above, silvery white below".
Affinities: B. brevis is close to B. macrolepidotus and B. batesii, but has a highest body. Although closely related to B. macrolepidotus, B. brevis can be distinguished from that species by its deeper body and the position of the outer premaxillary teeth which seem to be always aligned in a single row, while two of these teeth are shifted backwards in the adults of B. macrolepidotus. Finally, B. brevis has less scales along the lateral line than B. batesii (21-24 vs 29-31).
Remarks: four species, with limited distribution) are very close to B. macrolepidotus: B. batesii (Cameroon), B. brevis (some coastal rivers in Ghana and Nigeria), B. rhoddopleura (Lake Tanganyika) and B. schoutedeni (South Cameroon to Congo). A study in progress indicates that these species have characters which exhibit a clinal geographic variation. Similar, clinal variation was already observed in West Africa (Paugy, 1982 b). In anticipation of the conclusions of the ongoing study, B. macrolepidotus is generally considered the only species of this group present in Africa.
Diet
Remains of leaves were found in stomach contents (Trewavas & Irvine, 1947). Therefore, its diet seems to be close to that of the other species of the macrolepidotus group.
Distribution
Southern Ghana and southern Nigeria (Lagos and the Benue basin) (see also Faunafri).
This species is known from four locations (Ghana and Nigeria). The extent of occurrence is less than 20,000 km². Area of occupancy is thought to be more than 2,000 km².There is an ongoing decline in habitat quality due to oil exploration (Niger Delta) and deforestation (Ogun river basin).There are no data on fluctuation of population. The species therefore qualifies as vulnerable under Criterion B. As the species is restricted to four locations it also qualifies for Vulnerable D2.
Bibliography
Brycinus carmesinus (Nichols & Griscom, 1917)
Type and type locality
Alestes carmesinus/i> Nichols & Griscom, 1917: 682. Type locality: "Zambi", holotype AMNH n° 6330.
Synonyms
Alestes carmesinus Nichols & Griscom, 1917
Brycinus carmesinus Myers, 1929
Common names
Estonian: Karmiin-kardsalmler
Description
Diagnosis: the fronto-parietal fontanel is absent. The adipose eyelid is rudimentary. The head is broad and the supra-orbital bone is well developed. The snout is rather long and the jaws are equal. The humeral and precaudal spots are present. Gill rakers are short. On the specimen examined there are three distinct longitudinal dark lines along the flanks.
Measurements and counts of the original description and those of the holotype revised are given below.
Brycinus carmesinus: main morphological characters of types.
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Maximum reported size: 161 mm SL, 190 mm TL.
Colour: according to the original description "Colour dark along the back, pale below, a black humeral spot and a black blotch on peduncle extended forward to below dorsal as a vague dark stripe ; lower sides and cheeks rose red" (Nichols & Griscom, 1917).
Affinities: B. carmesinus is very close to B. grandisquamis and B. poptae. In B. carmesinus there are more predorsal scales than in B. poptae (11½ vs 8-9). Distinction with B. grandisquamis is less clear. Nevertheless, the holotype of B. carmesinus is very high and is outside of the limits of variations of B. grandisquamis. In the same way, the head is broader. B. carmesinus is only known by the holotype. So it will be certainly necessary to get further observation to have a good glance on the validity of this species. Indeed, this group is well known for its morphological plasticity function of its geographical distribution.
Distribution
Only known by the holotype from Zambi, lower Congo River in Democratic Republic of the Congo. However specimens recently collected in the Lefini River have tentatively been assigned to this species (AMNH) and the species may have a distribution extending into the middle Congo (see also Faunafri).
Brycinus carmesinus is only known by the type from Zambi, Zambia. The species may be more widespread than is currently known. More information is needed on the species distribution before an assessment can be made.
Major threats: none known.
Bibliography
Brycinus carolinae (Paugy & Lévêque, 1981)
Type and type locality
Alestes carolinae Paugy & Lévêque, 1981: 97-101. Type locality: "Niandan à Niandan (Guinée)", holotype MNHN n° 1980-1522, paratypes MNHN n° 1980-1523.
Synonyms
Alestes carolinae Paugy & Lévêque, 1981
Brycinus carolinae Paugy, 1986
Common names
Estonian: Niandani kardsalmler
Description
Diagnosis: body depth comprised about three times in standard length. Dorsal fin origin at about the same level as pelvic fin insertions. Jaws equal; premaxillary with two tooth rows, each comprising 8 teeth. Scale formula: 4½/24-26/3½. Anal fin with three spines and 12 or 13 branched rays. Lower (ceratobranchial) limb of first gill arch with 20 or 21 gill rakers. This species shows a sexual dimorphism affecting the anal-fin shape in adult males.
Measurements and counts of the original description are given below.
Brycinus carolinae: main morphological characters of types.
Maximum reported size: 104 mm SL.
Colour: body silvery, back darker and belly lighter. A rather broad (two scales wide) dark band running along the entire length of sides; a black humeral spot and a precaudal band, the latter extending unto part of caudal fin. Fins pale yellow in live specimens. After preservation in formalin, the longitudinal band becomes darker in males than in females.
Affinities: this species differs from B. imberi by its yellow fins (red in B. imberi) and its black longitudinal band (absent in B. imberi); and from B. nigricauda by the absence of the black band on each caudal-fin lobe (present in B. nigricauda).
Distribution
This species is only known from the Niandan River (a tributary of the Upper Niger basin) (see also Faunafri).
This species is restricted to two or three locations in the Upper Niger River. Potential threats due to deforestation and drought and its very restricted range, and it can be assessed the species as Vulnerable D2.
Major threats: No current threats known. There is a potential threats are deforestation and drought.
Bibliography
Brycinus comptus (Roberts & Stewart, 1976)
Type and type locality
Alestes comptus Roberts & Stewart, 1976: 270-271. Type locality: "Near Inga hydroelectric dam", holotype MCZ n° 50506, paratypes MCZ n° 48232
Synonyms
Alestes comptus Roberts & Stewart, 1976
Brycinus comptus Géry, 1995
Common names
Estonian: Kaunis kardsalmler
Description
Diagnosis: a moderately deep-bodied Brycinus with 10 dorsal and 17 anal fin rays; 23-26 scales in the lateral line series; 15 gill rakers on lower limb of first gill arch; outer premaxillary tooth row with 4 + 4 or 3 + 3 teeth nearly perfectly aligned with each other; coloration distinctive, with no tail light in live individuals.
Maximum reported size: 63 mm SL.
Colour: due to its coloration, B. comptus was recognized as a distinct species the moment it was collected. The entire body is lighter-colored and less dusky than in B. imberi. Live B. imberi are characterised by a tail-light, a highly reflective spot on the dorsal surface of the caudal peduncle, immediately behind the adipose fin. In day light this spot is usually bright orange. In preserved specimens it is represented by a light-colored, crescent-shaped spot, standing out clearly from the rest of the otherwise dark dorsal surface and from the black spots on the sides of the caudal peduncle which encroach upon it from below. The holotype of B. comptus had no tail-light when it was alive, and the preserved specimen has no indication of one. The dorsal surface, while darker than the rest of the body, is lighter than in B. imberi, and there is no light area atop the caudal peduncle. The black spot on the side of the peduncle is smaller than in B. imberi, and continues as a longitudinal band to the tips of the middle caudal rays. In imberi the spot continues onto the caudal base, but extends only half the length of the middle rays. In B. comptus the humeral spot is placed on the fifth, sixth and seventh scale rows behind the upper angle of the gill cover, whereas in B. imberi it is on the fourth and fifth scale rows. In the 63.0-mm paratype, after three years in preservative, an iridescent golden band still extends from the eye to the base of the caudal fin; immediately below this golden band, and above the lateral line scales, an iridescent violet and bluish-green band extends from the opercle to a point above the anal fin origin. Such coloration has not been recorded for any other Brycinus; it is suggestive of the iridescent coloration covering the entire body in mature male Phenacogrammus interruptus, a species endemic to the Congo basin, and one of the mort beautiful members of the family Alestidae.
Affinities: B. comptus superficially resembles B. imberi, but differs in numerous respects from that species. B. imberi taken at the same locality as the holotype have a slightly wider head; nostrils further apart; a larger mouth; larger teeth; outer premaxillary tooth row with 4 + 4 teeth, but second tooth lying further inside than the others; and 19-20 gill rakers on lower limb of first gill arch. The squamation also differs: B. comptus has 10 predorsal scales (versus 8-9 in B. imberi), and larger and less numerous scales on the base of the anal fin (see figure below). There are also important differences in coloration. Similar differences exist between the paratypes of B. comptus and specimens of B. imberi obtained at the market in Bangui at the same time.
Brycinus, squamation at base of anal fin: B. imberi, 53 mm; B. comptus, 55 mm.
According to Géry (1995) B. comptus has also the same set of characters as B. fwaensis. B. comptus is nevertheless twice as large s B. fwaensis. The two species have the dorsal fin in different position (slightly in front of the middle in B. comptus vs clearly behind midbody in B. fwaensis, and different colours in vivo. The humeral spots are slightly different in size and position, situated in an intermediate position in B. fwaensis, between that of B. imberi (anterior) and B. comptus (the most posterior). The caudal spots are also different, the extension on caudal fin much less conspicuous and narrower in B. fwaensis where the black pigment extends only onto two median rays.
Distribution
Only known from the type locality near Inga hydroelectric dam, Congo River (see also Faunafri).
Brycinus comptus is only known from the type locality near Inga hydroelectric dam, Lower Congo River. The species may be more widespread than is currently known. More information is needed on the species distribution before an assessment can be made.
Major threats: none known.
Bibliography
Brycinus derhami Géry & Mahnert, 1977
Type and type locality
Brycinus derhami Géry & Manhert, 1977: 618-621. Type locality: "Néro sur le Mont Klon (5°11'N-7°12'W), sud-ouest de la Côte d'Ivoire", holotype MHNG n° 1183.6, paratypes MHNG n° 1253.46-52
Common names
Estonian: Vandliranniku kardsalmler
Description
Diagnosis: fronto-parietal fontanel always present, even in adults. Adipose eyelid rudimentary. Dorsal fin origin at about the same level as pelvic fin insertions. Jaws equal; the 6 outer premaxillary teeth aligned in a single row. Scales formula: 5½/26-30/3½. Anal fin with three spines and 19-21 branched rays. Lower (ceratobranchial) limb of first gill arch with 12-14 gill rakers. This species shows a sexual dimorphism affecting the anal fin shape in adult males, which also have the first dorsal-fin rays prolonged into a long filament extending beyond the adipose fin when pressed to body.
Measurements and counts of the original description are given below.
Brycinus derhami: main morphological characters of types.
Maximum reported size: 82 mm SL.
Colour: sides silvery and fins colourless, except for the dorsal, which is wine-red in adult males. Body with a dark humeral spot and a distinct, anteriorly pointed precaudal blotch, the latter not extending unto caudal fin.
Affinities: B. derhami is closely related to B. longipinnis and can be confused with that species. However, these two forms can easily be distinguished by the shape of the precaudal blotch which is ovoid in B. derhami, but elongate and extends onto the caudal fin in B. longipinnis (see figure below).
Shape of the precaudal blotch in Brycinus longipinnis and B. derhami.
Brycinus derhami and B. longipinnis: main meristic characters.
Distribution
This species seems to be restricted to the small coastal basins in the southwest of Côte d'Ivoire (Nero, Dodo and Tabou) (see also Faunafri).
This species is known from at least three locations, in the southwest of Côte d’Ivoire (Néro, Dodo and Tabou). There is no known current threats but due to the limited range, and the potential threats from deforestation, water pollution and agricultural expansion the species is assessed as VU D2.
This species is locally threatened by water pollution from domestic sources. There is a potential threats from deforestation and agricultural expansion.
Bibliography
Brycinus epuluensis Decru, Vreven, Sadio & Snoeks, 2016
Type and type locality
Brycinus epuluensis Decru, Vreven, Sadio & Snoeks, 2016: 49-60. Type locality: “Ituri basin: Edoro River, upstream of the bridge, near the research camp at Edoro-Afarama, affluent of Epulu River, 1°33'01" N 28°30'41" E; Exp. Réserve Okapis, 6 Jul 2009”. Holotype. MRAC A9-029-P-0612, 85.1 mm SL; paratypes MRAC A9-29-P-0613, 1, 83.7 mm SL; MRAC A9-029-P-0573-0575, 3, 90.2-95.2 mm SL.
Description
Diagnosis: Brycinus epuluensis is distinguished from all species belonging to the macrolepidotus group by having a short snout (more than 3 times in head length vs. less than 3 times), and fewer premaxillary teeth (6-7, vs 8-11). It is distinguished from all species belonging to the longipinnis group by the absence of a fronto-parietal fontanelle in adults (larger than ca 75 mm SL) (vs fronto-parietal fontanelle always present), fewer lateral line scales (18-22 vs 25-36), and generally fewer anal-fin rays (iii12-15 vs iii14-25). It is distinguished from all species of the nurse group by having 6 (exceptionally 7) premaxillary teeth (vs 8-10, exceptionally 7). The species is most similar to B. imberi, from which it is mainly distinguished by fewer premaxillary teeth (6, exceptionally 7 vs 8, exceptionally 7), fewer lateral line scales (18-22 vs 21-31), and the presence of a black mid-lateral band.
Brycinus epuluensis: morphometric and meristic data (n = 53).
B. epuluensis is a medium-sized species. Body relatively slender (body depth at pelvic fins 27.9-34.0 % SL, mean 30.9), with greatest depth at vertical through dorsal fin origin. Dorsal profile straight along head, straight to slightly convex from occipital process to adipose fin, and slightly concave between adipose and caudal fins. Ventral body profile convex between isthmus and analfin base, straight to convex along anal-fin base, and slightly concave between anal and caudal fins. Caudal peduncle slightly longer than deep. Head narrow (width 13-15 % SL, mean 14.1); fronto-parietal fontanelle absent in adults (closes at ca 75 mm SL). Snout rounded and relatively short (7-10 % SL, mean 8.5), jaws isognathous, mouth terminal. Orbit relatively large, length larger than snout length. Upper jaw with two tooth rows. Six, exceptionally seven pluricuspid teeth in outer row of premaxilla, aligned in a single row, with a crenelated appearance and an enlarged median cusp flanked by one or two smaller cusps. Inner row of premaxilla with eight stout teeth, anteriorly with two blunt broad-based cusps, and with a large primary cusp flanked by several secondary cusps on posterior edge. Eight outer row teeth on lower jaw, each with a large central cusp and one to three secondary cusps on either side. Two outermost teeth much smaller than median six. A single pair of small conical teeth on inner row of lower jaw. Dorsal fin located at midbody, origin of pelvic fin at same level or slightly anterior to dorsalfin origin. Dorsal-fin margin straight to slightly convex. Caudal fin forked, with rounded lobes of equal size. Adipose fin inserted above posterior border of anal fin. Sexual dimorphism in anal fin shape with a concave distal border in males and a straight border in females. Body covered with well-developed, relatively large cycloid scales. Lateral line completely pored, with a low number of scales (18-22). Gill rakers long and slender, 10-13 on upper branch, 13-17 on lower of first gill arch; total number of gill rakers 25-30 (counted on 20 specimens). Vertebrae 33-34 excluding Weberian apparatus (counted on 20 specimens based on X-ray photographs).
Brycinus epuluensis: open mouth in lingual view.
Maximum reporteded size: 109.8 mm SL.
Colour:
Preserved specimens: dorsal and dorso-lateral parts of head and body olivebrownish, ventral parts of body light brown to yellowish; head yellow to silvery below eye. A broad blackish mid-lateral band, spanning one to two scale rows, from operculum to caudal-fin base. In males, band more pronounced than in females; in small specimens (smaller than ca 75 mm SL), band vague or even absent. Humeral and caudal spots always present. All fins greyish, except pelvic fin yellowish.
In vivo: dorsal parts of body olive-yellowish, ventro-lateral and ventral parts grey to silvery. Dorsal, caudal and anal fins olive-yellowish; pectoral and pelvic fins grey to silvery; adipose fin orange. Black mid-lateral band on flank in males, apparently absent in females. Humeral and caudal spots present in both sexes.
Affinities: B. epuluensis most closely resembles the widespread species B. imberi from the nurse group, although it has a broad black mid-lateral band on the body, which is absent in B. imberi. This black band is, however, also present in specimens from the neighbouring population in the Ituri River itself. Brycinus epuluensis differs from the types of B. imberi and its five junior synonyms, as well as from the neighbouring Ituri population, mainly in having only 6 instead of 8 premaxillary teeth, arranged in a single row. This low number of premaxillary teeth is characteristic for species of the longipinnis group. However, B. epuluensis differs from all members of the longipinnis group by the absence of a fronto-parietal fontanelle in adults and the following combination of characteristics: 18-22 lateral line scales and 12-15 branched anal-fin rays. The Ituri population could not be separated from B. imberi and most of its synonyms on morphometrics, but does differ by the presence of the black mid-lateral band.
Distribution
Brycinus epuluensis is endemic to the Epulu River and its affluents. The Epulu River is the most important right bank affluent of the Ituri River, from which it is separated by the Arabia waterfall. Within the Epulu basin, B. epuluensis is captured in the main stream and its affluents, the Lélo, Edoro and Nduye rivers (see also Faunafri).
IUCN assessment
Not evaluated.
Bibliography
Brycinus ferox Hopson & Hopson, 1982
Type and type locality
Alestes ferox Hopson & Hopson, 1982: 299-303. Type locality: "1 kilometer west of North Island, Lake Turkana, depth 38 meters, Kenya, 31/8/1973", holotype BMNH n° 1978.5.16.1, paratypes BMNH n° 1978.5.16.2-30; 1978.5.16.31-36.
Synonyms
Alestes ferox Hopson & Hopson, 1982
Brycinus ferox Seegers et al., 2003
Common names
English: Large-toothed Lake Turkana robber (Kenya)
Estonian: Turkana kardsalmler
Description
Diagnosis: based on the holotype and on 35 paratypes of 25-81 mm SL. Length 3.1-4.0 times the maximum depth and 3.0-3.4 times the length of the head. Eye 2.6-3.2 times in the length of the head, 0.50.7 times in the interorbital width (measured across the frontals) and 0.7-0.9 times in the length of the snout. The premaxilla is elongated compared with other Brycinus spp. to give the snout a distinctive muzzle-like appearance. Dorsal profile of head partly concave. Mouth large. Caudal peduncle 1.1-1.4 times as long as deep. Pectoral fin 0.5-0.7 times the length of the head. Dorsal fin 0.6-0.8 times as long as the head with II 8 rays. Anal fin rays usually III 13 (f=30), more rarely III 14 (f=3) or III 12 (f=2). In mature males the central rays of the anal fin are elongated and expanded as is usual in Brycinus and related genera. The scales are thin and readily detached in the course of capture in trawl or metre townet hauls. Only the holotype was caught with the scales intact. The squamation was as follows:- lateral line scales 36, scales between the lateral line and the mid-dorsal lire near the origin to the dorsal fin 6, scales between the lateral line and the mid-ventral line 3, scales round the caudal peduncle. Gill rakers 19-23 (M=21). Number of vertebrae 35-38 (M=37).
The teeth are unusually long, sharply pointed and fang-like for an Brycinus. Outer row of premaxilla formed by 8, more rarely 10, unicuspid teeth situated anteriorly. Each tooth consists of a squat cylindrical base produced distally into a slender, curved caniniform cusp. The central teeth of the outer row tend to point forwards and downwards and the more lateral teeth downwards and backwards. Due to their position on the anterior margin of the premaxilla, the teeth often protrude forwards beyond the fleshy part of the snout and the upper lips, and are visible when the fish is viewed from above. Eight to ten pluricuspid teeth form the inner row of the premaxilla. The four anterior teeth, which have noticeably bulbous bases, are more massive than the adjacent teeth on the outer row. Each inner anterior tooth bears a well developed backward-curving caniniform cusp flanked on each side by two insignificant conical cusps, the outer of which are often barely discernable. The posterior teeth of the inner premaxillary row, which are inserted on the lateral margin of the jaw behind the row of outer teeth, are smaller than the anterior pluricuspids. The principal cusps of the posterior teeth are also caniniform but the subsidiary cusps, which usually number 2 or 3, are larger than those of the anterior premaxillary series, and the hind teeth thus appear less fang-like. The lower jaw is furnished with an outer row of 8-12 (usually 10) teeth bearing 3-5 sharp cusps. As in the pluricuspid teeth of the upper jaw, the principal cusp is acutely pointed, backward curving and caniniform, up to six times the length of the largest subsidiary cusp. The size of the teeth of the lower jaw tends to decrease posteriorly and the series terminates on either side with a relatively small and insignificant tooth. Two strongly decurved, backward directed, hook-like unicuspid teeth lying adjacent to one another, form the inner tooth row of the lower jaw.
Although the dentition of B. ferox, with the series of fang-like teeth on both jaws, superficially resembles Hydrocynus spp., the teeth do not interlock in the closed position. In B. ferox the upper teeth shut forward of the lower teeth and the fish is thus noticeably prognathous.
Summary of morphometric data: based on measurements obtained from the holotype and 29 formalin-fixed paratypes ranging from 25-81 mm SL. The measurements have been expressed as a percentage of the standard length (see table below).
Brycinus ferox: morphological characters (n = 29) (*bony interorbital width measured across frontals).
Maximum reported size: 120 mm FL.
Colour: in living specimens, pale fawn with silver scales, darker on the dorsal surface. Both lobes of the caudal fin marked with red chromatophores which are interspersed with yellow chromatophores on the lower lobe. In formalin-fixed specimens the dorsal surface is lightly patterned with melanophores, heavier in a band on the mid-dorsal line. Characteristic patches of black pigment are present on the snout, on the lower jaw and on the mid-lateral portion of the caudal peduncle. In some specimens, a small but distinct black spot is present on the flanks posterior to the operculum. Distal margin of caudal fin with broad edging of black pigment.
Affinities: readily distinguished from other Brycinus by the sharply pointed fang-like teeth and by the muzzle-like prognathous snout (see figure below).
Shape of the teeth and snout is very different in B. ferox and B. nurse.
The unusual dentition has probably evolved as a response to the pelagic habits of B. ferox in Lake Turkana, resulting in the adoption of a specialised diet, which in larger individuals includes a high proportion of prawns and small fish. In collections of small fish from Lake Turkana B. ferox is also distinguished from B. nurse by the lack of heavy pigment in the region of the horizontal myoseptum. Easily separated from B. minutus by the presence of black pigment on the snout, mid-dorsal line, caudal peduncle and caudal fin. Matures at a larger size than either the Lake Turkana population of B. nurse or B. minutus.
Reproduction
The species spawns within the lake. Matures at 6-8 cm FL.
Diet
Chiefly prawns, zooplankton and insects with an increasing proportion of small fish in larger individuals.
Distribution
Endemic to Lake Turkana. A pelagic species, at times abundant, occurring in the open waters throughout the lake. During daylight hours situated in the midwater scattering layer. Disperses throughout the surface layers after dark and may occasionally occur inshore on steeply-shelving coastlines rivers (see also Faunafri).
No noticeable threats or decline.
Bibliography
Type and type locality
Brycinus fwensis Géry, 1995: 48-50. Type locality: “Lake Fwa, draining into Lubi River, Kasai, ca 155 km eats of Katanga, Kasai Occidental, Zaïre (ca 6°30'S and 23°E)”, holotype MHNG n° 2572.07, paratypes MRAC n° 95.026.P.0001-0002
Common names
Estonian: Fwa kardsalmler
Description
Diagnosis: a small Brycinus species, belonging to the group with a small, purely parietal, fontanel, at least in the young, more than 3 external premaxillary teeth (on each side), only 4 scales from dorsal to lateral line, few longitudinal scales (22-24) and few gill-rakers (10-11/ 13-14 (15?). Distinguished by the peculiar position of the humerai spot, more caudad than (when present) that of any other species except the briefly described B. comptus from the rapids of the lower Congo.
Body moderately elongate, the greatest depth a little in front of dorsal, 3.10-3.30 in SL; length of head also moderate, 3.15-3.40 in SL; dorsal fin clearly behind midbody, origin just above pelvics, formula ii,8(i), predorsal length 53-55% of SL, 0.89-0.98 in postdorsal length; anal fin border concave, formula iii,12-15 (mode 13), last ray double; pectorals i,13, not reaching base of pelvics; pelvics i,8, not reaching first anal fin ray, prepelvic distance 50.0-54.0% of SL; prepelvic region flattened, the edges rounded; caudal fin without a median lobe; caudal peduncle moderately deep, its depth 1.10-1.45 in its length, 11.012.0% of SL. The scales are of the alestid type, corresponding to that figured in Géry & Mahnert (1977) for Brycinus derhami. The nucleus is central and the radii, diverging from the nucleus, more numerous (6-7). The scale is higher than long. A number of scales have the radii anostomosed at the centre, which is probably characteristic for regenerated scales (G. Loubens, pers.comm.), and of no value in a classification of a characiform. Lateral line complete, with 22-24, mostly 23 (5 ex.) or 24 (5 ex.) scales, running on caudal peduncle on the last transverse row, with the terminal 1 or 2 scales on caudal fin. There are 11/2 transverse scales from lateral line to root of pelvics (31/2 to middle of ventral surface), 4 above from dorsal to lateral line (41/2), 91/2 predorsal scales in a rather irregular row and 10 around caudal peduncle. Eye 3.0-3.40, interorbital 2.85-3.20, apparent length of maxillary 5.10-7.30, snout in oblique 3.10-3.95 in the length of head (without membrane). In lateral view, the snout is moderately elongate and pointed, the maxillary is shorter than in some other Brycinus, and the mandible is in advance of the premaxillary bone. The fontanel is small and always present. It is triangular and bounded only by the parietals; it does not encroach on the frontals; the suture of S03-4 is well above cheek's angle; 2nd suborbital has a naked zone below, 3rd suborbital has a naked zone in its anterior as well as in its posterior part, and almost reaches the suborbital canal at the angle of the preoperculum, covering 85% (in the smallest) to 90% (in the largest) of the cheek; 3 postorbitals well developed. Supraorbital present, extending from just behind the posterior nostril to the level of the middle of the pupil; its anterior part developed, its posterior part narrow, separated from the last circumorbital by the frontal. Three to five tricuspid anterior premaxillary teeth (on each side), regularly set, distributed as follows: 3-3 (f 1); 3-4 (f 2); 4-4 (f 5); 4-5 (f 2); 5-5 (f 1); 4 tri- to quincuspid inner teeth (on each side), concave in front, with two supplementary cusps (i.e. shoulders or heels), in the upper part of the concavity, distinguishing these teeth from those of the Petersiini which are simply compressed and not concave in front; the median tooth with 3 cusps and two heels, the 2nd with 5 cusps and two heels, the 3rd and 4th with 4 or 5 cusps, not well defined, and no heels; 3 strong quincuspid teeth on dentary bone, followed by a smaller, tricuspid tooth; IMT present, strong. 1011/13-14 (15?) gill-rakers present on the first arch. An anterior, very rudimentary, adipose eye-lid. The posterior, tapered part of the gas-bladder does not reach the level of the first anal fin ray.
Maximum reported size: 39 mm SL.
Colour: after preservation, the colour pattern is as follows: a pale lateral band runs from the operculum to the caudal peduncle, along the medial axis. A conspicuous caudal spot, not sharply delimited, pointed in front, rounded behind, is separated by a curved line from a very faint extension over the middle caudal rays, and does not reach to their end. A humerai spot, more posteriorly placed than in most Brycinus spp., is situated between the anterior border of the operculum and the first dorsal ray level, above the 5- 6th scales of the lateral line, slightly under the levelof the lateral band. It is more or less oval with the long axis vertical. There are some chromatophores on anal fin base. .
Affinities: according to its collector (H. Bleher, pers.comm.), who spent some time collecting in the region and diving in the lake, no larger specimens than those collected were seen. One may thus assume that Brycinus fwaensis is a species with a permanent fontanel. Following that hypothesis, running through the identification key of the recent revision of the Alestes-Brycinus group (Paugy, 1986), one finishes with a species from Angola, B. humilis (Boulenger, 1905), which has no humeral spot, 29-32 scales in lateral line (cf 22-24) and 19-20 lower gill rakers (cf 13-14 (possibly 15).
One has nevertheless to consider the possibility that the specimens of the new species are composed of juveniles, which close their fontanel when adult. It is thus necessary to compare Brycinus fwaensis with the several species that lack a fontanel at least when adult, and share the following characters: more than 3 external premaxillary teeth, 4 scales from dorsal to lateral line, and a short anal fin. According to the revision cited above, 15 species belong to this Brycinus-group. Seven, being B. bimaculatus, B. carolinae, B. kingsleyae, B. nigricauda, B. opisthotaenia, B. peringueyi and B. taeniurus, have a very different colour pattern (usually a longitudinal band beginning under dorsal fin and a humerai spot, when it exists, situated anteriorly), and more lateral line scales and gill-rakers. Five others, B. carmesinus, B. grandisquamis, B. poptae, B. rhodopleura and B. schoutedeni, have no fontanel even when young, more gill rakers and usually more lateral line scales. The humerai spot, when present, is closer to the operculum; B. grandisquamis and B. poptae may have as few as 22-24 lateral line scales, but they have a shorter anal fin (respectively 9-12 and 10-11 branched rays, cf 12-15, mode 13 in B. fwaensis) as well as a different colour pattern. Of the three remaining species, B. abeli and B. jacksonii have likewise more scales and more gill-rakers; B. imberi, a very common species with a large geographical range, may have relatively few scales and gill-rakers in some parts of Africa, but never in the Congo, as counted by Paugy (1986); its humerai spot is, like in the other Brycinus with a humerai spot, closer to the operculum than that of B. fwaensis. In specimens of B. imberi from Kinshasa, lower Congo (collected by H. Bleher Sep.14, 1986, Reg.N° G. 784 a-c), the large, rounded spot is above the 3rd and 4th scales of the lateral line (cf 5-6th), the top of the head is flat and there is a prominent snout, and the fontanel is closed in the smallest fish (about 70 mm SL). The scales, though of the same type, are as deep as long, and there are 26 lateral line scales. The anal fin has 14-15 branched rays and there are 16 gill-rakers on the lower arch.
Finally, B. comptus from Lower Congo (not mentioned by Paugy, 1986, and not seen by me), was described as close to B. imberi: it would then belong to the genus Brycinus and should be compared with B. fwaensis. It has approximately the same set of characters as B. fwaensis, although only a few were described (the condition of the fontanel is not mentioned). B. comptus is nevertheless twice as large as B. fwaensis.
The two species have the dorsal fin in different positions (slightly in front of the middle in B. comptus cf clearly behind midbody in B. fwaensis), and different colours in vivo.
The humeral spots are slightly different in size and position, situated in an intermediate position in B. fwaensis, between that of B. imberi (anterior) and B. comptus (the most posterior).
The caudal spots are also different, the extension on caudal fin much less conspicuous and narrower in B. fwaensis, where the black pigment extends only onto two median rays.
Moreover it is unlikely that a species characteristic of rapids would live in the tranquil waters of Lake Fwa , where the ichthyofauna is known to be highly endemic. However, the presence of B. comptus in the Bangui market, very far from the Inga Dam, shows that the poorly known latter species may have an extensive range.
Distribution
This species is sympatric in Lake Fwa with another alestid, Micralestes fodori Matthes, 1965. Both species occur only in the lower part of the lake (Lake Fwa is divided by a narrow rapid), but the biotopes of the two species are distinct. Micralestes fodori lives in the more open waters of the lake whereas B. fwaensis is found among aquatic plants around the edges (see also Faunafri).
This species is widespread or without major threats throughout the Central Africa assessment region and is assessed as Least Concern.
No major threats known.
Bibliography
Brycinus grandisquamis (Boulenger, 1899)
Type and type locality
Alestes grandisquamis Boulenger, 1899: 85. Type locality: “Bas Congo et Matadi”, syntypes MRAC n° 354-355, , 800, 802, 1195
Synonyms
Alestes grandisquamis Boulenger, 1899
Brycinus grandisquamis Myers, 1929
Brycinus grandisquamis grandisquamis Hoedeman, 1951
Brycinus grandisquamis batesi Hoedeman, 1951: 5
Common names
Bemba: Chikama/Chitololo/Mutula (Zambia)
Chokwe: Mbungu/Susulu/Tshikanga (Angola)
English: Pinkfin Alestes (Zambia)
Estonian: Haljas kardsalmler
Finnish: Sinisuomualesti
Kele: Lilongo/Walo (Democratic Republic of the Congo)
Lombo: Walo (Democratic Republic of the Congo)
So: Walo (Democratic Republic of the Congo)
Description
Diagnosis: cranial bones, particularly the supra-orbital, are thick. In young specimens, teeth of the external premaxillary are on a single row. Later in adults two teeth are shifted behind compared to the others. The two first anal-fin rays are strongly ossified and cannot be folded without breaking. The first rays of ventral and pectoral fins are also slightly ossified. All specimens have a humeral spot and a precaudal blotch extends to the hind margin of caudal fork. In all specimens examined, adipose eyelid is rudimentary, the fronto-parietal fontanel is absent and the swim bladder not extended posteriorly beyond the anus.
Measurements and counts of the original description, those of the types revised, those of Congo River basin and those of Angola are given below.
Brycinus grandisquamis: main morphological characters of types and additional material (* total length; ** up to the occiput).
Maximum reported size: 260 mm SL.
Colour: in alcohol, specimens are brown. In live “Back red-brown coppered, flanks red-coppered and belly yellowish. The lower part of the head, the operculum and the flanks are carmine” (Matthes, 1964a). There is a pale dark spot at the base of the caudal-fin; eye carmine; dorsal-fin brown-red, adipose-fin red-rust, caudal-fin yellow-rust with blackish margins. Paired fins yellow. The first rays of the pectoral-fins blackish. In mature males, flanks are reddish particularly the lower part, belly is yellow-salmon, unpaired fins red-wine and paired fins yellow or red. In young specimens, the spot of the caudal peduncle is bordered of white. This particular coloration is also very visible in water.
Affinities: B. grandisquamis is close to the two sympatric Congolese species B. poptae and B. carmesinus. However, B. grandisquamis has more predorsal and lateral line scales than B. poptae (respectively 10½-12 vs. 8-9 and 24-29 vs 21-23). B. grandisquamis is less depth than the alone known specimen of B. carmesinus (SL/ body depth <3 vs >3.2). See also comment in B. carmesinus sheet.
Diet
Like all the species of the macrolepidotus group, B. grandisquamis feeds mainly on exogenous items, particularly leaves and insects (Hulot, 1950; Matthes, 1964a). However, in a small specimen, some remains of aquatic insects were also found (Chironomids larvae and Ephemeroptera nymphs).
Distribution
B. grandisquamis is found in the entire Congo basin from the lower to the upper course, included Kasai sub-basins Luapula-Mweru and Chambezi-Bangweulu systems. But it was never found in the Sangha sub-basin (see also Faunafri).
The species is widespread or without major threats throughout the Central Africa assessment region and is assessed as Least Concern. No major threats known.
Bibliography
Brycinus humilis Boulenger, 1905
Type and type locality
Alestes humilis Boulenger, 1905: 458. Type locality: “Quanza River, Angola”, holotype BMNH n° 1905.5.29:66.
Synonyms
Alestes humilis Boulenger, 1905
Brycinus humilis Géry, 1968
Common names
Bemba: Ntuntu (Zambia)
Estonian: Angola kardsalmler
Finnish: Angolantetra/Messinkialesti
Description
Diagnosis: in all specimens examined, the adipose eyelid is rudimentary and the fronto-parietal fontanel is well developed. There is no humeral spot, but there is a precaudal blotch continuing backwards on median caudal fin rays. Gill rakers are numerous and thin, but rather short. The eight premaxillary external teeth are disposed on a single row.
Measurements and counts of the original description, that of the type revised and those two specimens from Angola are given below.
Brycinus humilis: main morphological characters of types and additional material (*total length).
Maximum reported size: 76 mm SL, 95 mm LT.
Colour: in the original description, Boulenger (1905) notes “Olive above, silvery beneath; a black spot on the caudal peduncle, extending on the median caudal rays”. In specimens conserved in alcohol, there is along the flanks a rather large silvery band onto 3 or 4 scales.
Affinities: B. humilis is close to B. imberi. B. humilis has a more elongated body (> 3½ in B. humilis vs < 3½ in B. mberi). B. humilis has a long fronto-parietal fontanel, in B. imberi the fontanel is pore like. In B. imberi, the silvery band is absent. The two species are sympatric in the Quanza River, but B. imberi is absent in Cunene River and in the Cubango-Okavango system. On the other hand B. humilis is absent in the Congo basin.
Distribution
B. humilis was described from the Quanza River and was found in the Cubango River and in the Okavango basin. Its presence in the Luapula River must be checked and the specimen of the Luembe River is certainly a error in the locality. Finally specimens from Eala (central Congo basin) and from the Lulua River (Kasai system) are misidentifications of B. imberi basin (see also Faunafri).
This species is known from three catchments: Kwanza, Kunene, Okavango River. No obvious threats are known.
Major threats: no conservation and biological works/projects have been done in Angola, therefore threats are not known.
Bibliography
Brycinus imberi (Peters, 1852)
Types and type localities
Alestes imberi Peters, 1852: 276. Type locality: “Zambesi River”, syntypes ZMHU n° 3574.
Alestes fuschii Boulenger, 1899: 83. Type locality: “Bome (rivière des crocodiles), Stanley Pool (région des chutes) et lac Léopold II”, syntypes MRAC n° 796,797,798,799.
Alestes lemairii Boulenger, 1899: 84. Type locality: “Lac Moéro”, syntypes MRAC n°221.
Alestes fuschii var. taeniata Pellegrin, 1903: 328. Type locality: “Ouéllé”, holotype MNHN n° 1903-191.
Alestes curtus Boulenger, 1920b: 16. Type locality: “Avakubi”, holotype MRAC n° 7484.
Alestes bequaerti Boulenger, 1920b: 148. Type locality: “Avakubi”, holotype MRAC n°14538.
Synonyms
Alestes imberi Peters, 1852
Brachyalestes imberi Günther, 1864
Alestes fuschii Boulenger, 1899
Alestes lemairii Boulenger, 1899
Alestes fuschii var. taeniata Pellegrin, 1903
Alestes curtus Boulenger, 1920b
Alestes bequaerti Boulenger, 1920b
Alestes humilis (non Boulenger) Pellegrin, 1928
Brycinus imberi Myers, 1929
Brachyalestes imberi affinis Hoedeman, 1951
Brachyalestes imberi imberi Hoedeman, 1951
Brachyalestes imberi curtis Hoedeman, 1951
Brachyalestes imberi kingsleyi Hoedeman, 1951
Myletes imberi Poll, 1976
Common names
Adangme: Tewe-kpiti (Ghana)
Afrikaans: Imberi (South Africa)
Baoulé: Adjoua ôclair (Cote d'Ivoire)
Bemba: Imene/Insaku/Nsaku/Nsakwila (Zambia)
English: Characin (Ghana), Imberi (South Africa, Tanzania, Zambia), Silversides (Ghana), Spot-tail (Malawi), Tanzania), Spot-tail Robber (Tanzania)
Estonian: Laiksaba-kardsalmler
Ewe: Dzogla/Dzogla dzevui (Ghana)
Finnish: Lyhtyalesti/Punaevätetra
Ga: Tewe kpiti (Ghana)
German: Roter Kongosalmler
Guro: Woueimatin (Cote d'Ivoire)
Kele: Elengeli/Ituku/Wakaka (Democratic Republic of the Congo)
Lombo: Gelengeli (Democratic Republic of the Congo)
Nyanja: Mberi/Nkhalala (Malawi)
So: Gelengeli (Democratic Republic of the Congo)
Swahili: Bembe/Beme/Mansali/Ngalala/Sandowe (Tanzania)
Wolof: Dabé (Senegal)
Description
Diagnosis: parietal fontanel pore-like in very young individuals, disappearing with growth. Dorsal fin origin at about the same level as pelvic-fin insertions. Jaws equal; premaxillary with two teeth rows, each comprising 8 teeth; in larger individuals, two teeth of the anterior row become dislodged, thus forming a second row. Scale formula: 4½/21-31/3½. Anal fin with three spines and 11-16 branched rays. Lower (ceratobranchial) limb of first gill arch with 16-20 gill rakers. This species shows a sexual dimorphism affecting the anal-fin shape in adult males.
Measurements and counts of the original description, that of the holotype revised and those of specimens from Zambezi (Zimbabwe), Limpopo (South Africa) and Mono (Togo) are given below.
Brycinus humilis: main morphological characters of types and additional material.
Maximum reported size: 167 mm SL, 199 mm LT.
Colour: sides silvery, back darker (greenish or brownish) and belly lighter. Body with a black humeral spot and a black blotch on caudal peduncle, the latter sometimes extending partially or totally unto caudal-fin rays. Colour of fins variable with hydrographic basins. Rayed fins yellowish or reddish and adipose fin red in the Congo basins, Ghana and South Africa. In the Zambezi and Lake Rukwa, paired fins yellow and adipose fin black. In Côte d'Ivoire and Togo, rayed fins, as well as adipose fin vermilion red, except in the River Cess (Nipoué), where the species has more brownish fins.
Affinities: B. imberi can be easily distinguished from B. nurse and B. affinis in the number of scales above the lateral line (4½ vs 5½) and from B. taeniurus, B. bimaculatus, B. opisthotaenia, B. peringueyi and B. kingsleyae by the absence of a black lateral marks on the body. Three endemic species border the geographical distribution area of B. imberi: B. abeli in the Ubangi River, B. nigricauda in the Cess (Nipoué) River and B. carolinae in the Upper Niger basin. The difference between all these species is weak and the difference is focused on coloration. B. abeli has no humeral spot, B. nigricauda has black edges to the caudal-fin lobes and B. carolinae has a large black band on the flanks. All these coloration characters are absent in B. imberi.
Growth
All the studies carried out show that the growth of females is faster than that of males. In the lake Kariba, B. imberi reaches about 90 mm SL in 2 years (Balon, 1971), while in the Lake Chivero (formely called Lake McIlwaine) (Zimbabwe), at 1 and 2 years the size of B. imberi (males and females) is respectively 98 and 126 mm SL (Marshall & Van der Heiden, 1977). This difference reflects certainly the rich food resources available in Lake Chivero (see § “Diet” below). From their data, we have computed the different parameters of the Von Bertalanffy equation, which are respectively L∞ = 178.37 SL mm et km (monthly) = 0.065. The L∞ value is in conformity with the maximal size reported which is 189 mm SL. In Côte d'Ivoire, the only results are based on fishes reared in ponds (Paugy, 1979-80a). They are only indicative and reveal that the growth is more or less the same than in Zimbabwe for juveniles and less fast for adults. This result depends certainly of the farming conditions.
Brycinus imberi: growth in two different African provinces.
Reproduction
In Côte d'Ivoire, the sexual maturity is reached during the first year at respectively 70 and 60 mm SL for females and males (Paugy 1979-80). In Lake Kariba, both males and females reached sexual maturity at less than 100 mm SL (Bowmaker, 1973, in Marshall, 2011). In Lake Chivero (formely called Lake McIlwaine) (Zimbabwe) the first maturity is reached during the second year at respectively 110 and 125 mm SL for males and females. In the Kruger National Park and in the Natal Province (South Africa), the sexual maturity is reached at about 100 mm, but the age is not precised (Crass, 1960). In this austral zone, spawning is grouped and takes place once a year during the flood (Pienaar, 1968; Marshall & Van der Heiden, 1977) (see figure below) and the the fish lay in the flood plains (Balon & Coche, 1974; Bell-Cross, 1976).
Brycinus imberi: breeding season in Lake Kariba (1997-1998) and Lake Chivero (1974-1976) (redrawn from Marshall, 2011).
Breeding females in Lake Chivero tended to be more fecund than those in Lake Kariba, the fomer producing up to 50 000 eggs compared to 20 000 eggs in Lake Kariba. The relative fecundity was also much greater, with 140 mm females from Lake Chivero producing an average of nearly 500 eggs per gram of body weigth, while a 140-mm fish from Lake Kariba produced around 130-250 eggs per gram (Marshall, 2011). This differences reflect the relative productivity of the two lakes: Lake Chivero is eutrophic and highly productive while Lake Kariba is oligotrophic with much lower productivity.
In Côte d'Ivoire, the results differ according to the authors. For Planquette & Lemasson (1975) the spawning takes place once a year during the flood in June-July and for Roest (1974), there is no spawning period well defined. In fact in all the Côte d'Ivoire Rivers, there are, all during the year, fish with active gonads (Paugy 1979-80; Albaret, 1982). That confirms the Roest results. Some observations in the Mono River (Togo) confirm the results from Côte d'Ivoire. Therefore, the reproductive parameters of B. imberi are different according to geographical regions. It seems that the species adapts its reproductive features with the hydrological conditions. Thus, when there are floodplains, the populations spawn once a year during the flood. Conversely, when the floodplains are absent the spawning takes place all during the year. This type of adaptation exists also for B. macrolepidotus (Paugy, 1982b). This particular breeding adaptation is certainly the reason of the ubiquistic distribution of these two Brycinus species.
Brycinus imberi: parameters of fecundity in Côte d'Ivoire.
The other data carried out are more fragmentary because they concern samples less important. In three females from the Mono River (Togo), we counted from 6,400 (100 and 105 mm SL) to 9,700 eggs (117 mm SL). In the Lake Kariba, the fecundity estimation is 166,000 eggs/kg (Balon & Coche, 1974). In Kruger National Park (South Africa), a ripe female had 14,000 eggs (138 mm SL). In Lake Chivero (formely called Lake McIlwaine) (Zimbabwe) the average fecundity of a female measuring 160 mm is of 30,000-40,000 eggs (Marshall & Van der Heiden, 1977). When gonads are ripe, eggs are yellow-orange and measure approximately 1 mm diameter.
Diet
Some little detailed studies are summarized in the table below:
Brycinus imberi: diet in some different regions of Africa.
Two more detailed studies were carried out in Côte d'Ivoire and in Zimbabwe. In the rivers from Côte d'Ivoire, B. imberi feeds mainly on aquatic insects but eats also exogenous items such as terrestrial insects and plants (Vidy, 1976; Mérona, pers. com.).
In Lake Chivero (formely called Lake McIlwaine) (Zimbabwe), B. imberi has a various but seasonal diet. From April to November fishes eat mainly terrestrial insects and from December to March they mainly feed on Chironomids. Plants and zooplankton are also sometimes found in the stomach contents of this species (Marshall & Ven der Heiden, 1977).
Brycinus imberi: seasonal variation of diet in the Lake Chivero, July1974 to June 2015 (from Marshall & Ven der Heiden, 1977).
According to Marshall (2011), in Zimbabwe, B. imberi has a varied diet, but feeds primarly on terrestrial insects that fall into the water, the larvae and pupae of aquatic insects, and plant material (especially seeds). In lake Kariba they fed mostly on terrestrial insects, especially the woodboring beetles that they were abundant in the drowned trees, Potamogeton seeds, and crustacean zooplankton and shrimps Caridina nilotica. By contrast, fish from the Mwenda River mostly fed on the larvae and pupae of the midge Chaoborus spp. and fish, which suggests that their diet varies according to whatever might be available at the time.
Populations
Taking account the anal fin branched rays and the lateral line scales number, it is noted differences between the different populations. As noted by Daget & Iltis (1965), Congolese populations have generally more anal fin branched rays than those of Côte d'Ivoire. But this criterium, as others, does not allow to make a distinction between sub-species.
Brycinus imberi: meristic characters in different rivers of Africa.
Brycinus Imberi: anal fin rays mean number vs lateral line scales mean number in different basins of Africa.
Habitat
B. imberi is mainly encountered in medium- and large-sized streams. The species exists in medium-sized artificial or natural lakes but never in very large ones like Lake Tanganyika or Lake Malawi, excepted in their tributaries. If B. imberi was abundant in the middle Zambezi, it is now scarce in the Lake Kariba dam. According to Balon (1971) the actual absence of hydrological seasonality in the large dam is certainly the reason of this scarcity. Some authors think also that the relatively high salinity would be the reason of the absence of B. imberi in large lakes.
Distribution
Described from the Zambezi River, this species is found in all the middle and lower Zambezi basin, particularly in the Cubango-Okavango system. In Eastern Africa, B. imberi was found from the Wami River (northern limit) to the Pongola River (Southern limit). In the Congo basin it is found from the lower to the upper river basin up to upper Katanga tributaries, the Luapula-Mweru-Bangweulu system and the upper Sangha tributaries. Along the central werstern coast, B. imberi seems to be only present in the Quanza River (Angola) and Nyanga River (Gabon). Finally very far from this geographical distribution, B. imberi is also found in western Africa from the Cess (Nipoué) River in the west (Liberia, Côte d'ivoire) to the Mono River in the east (Togo) (see also Faunafri).
This species has a wide distribution, with no known major widespread threats. It is therefore listed as Least Concern. It has also been assessed regionally as Least Concern for central, eastern, southern and western Africa.
This species faces different threats in different regions:
Bibliography
Brycinus intermedius (Boulenger, 1903)
Type and type locality
Alestes intermedius Boulenger, 1903: 22. Type locality: “Kribi River”,syntypes BMNH n° 1902.11.12:106-108.
Synonyms
Alestes intermedius Boulenger, 1903
Alestobrycon intermedius Hoedeman, 1951
Brycinus intermedius Géry, 1968
Common names
Estonian: Vahelmine kardsalmler
Hausa: Kawara (Nigeria)
Kanuri: Egbagi/Kaya (Nigeria)
Yoruba: Ajarapo (Nigeria)
Description
Diagnosis: fronto-parietal fontanel always present, even in adults. Dorsal fin origin at about the same level as pelvic fin insertion. Jaws equal; the 6 outer premaxillary teeth aligned in a single row. Scale formula: 6½/33-35/3½. Anal fin rays III-19-21. Gill rakers on lower limb of first arch 12-15. This species exhibits sexual dimorphism affecting the anal fin shape in adult males, which also have the first rays of dorsal and pelvic fins filamentous, the dorsal filament extending beyond adipose fin when pressed to body. Dentition rather peculiar, since none of the teeth in the second row are molariform and those which are excavated are much less so than in other Alestes and Brycinus species (see below).
Brycinus intermedius: teeth shape of the second premaxillary row.
Measurements and counts of the original description, that of the two syntypes revised and those two specimens from the Kribi River are given below.
Brycinus intermedius: main morphological characters of types and additional material (* total length).
Maximum reported size: 80 mm SL.
Colour: very similar to that of B. longipinnis with which it can be confused, but the latter species has a lower number of scale rows above the lateral line. There seems to be no humeral spot, but a precaudal blotch is rather well developed and extends to the hind margin of caudal fork.
Affinities: B. intermedius is close to B. bartoni, B. longipinnis, B. derhami and B. tholloni. It is distinguished from the three first by higher number of scales above the lateral line (6½ vs 5½) and from the last by lesser number of branched anal-fin rays (19-21 vs 22-25) and lateral line scales (31-34 vs 34-38). Moreover B. intermedius does not have humeral spot whereas this one is present in B. tholloni. Finally, these two species are not sympatric. The first seems to be endemic in the Kribi River (Cameroon) while the second is found in the coastal basins from Congo and Gabon.
Distribution
B. intermedius was described from the Kribi River (Cameroon). Later Boulenger reported the species from the Ogowe (Boulenger, 1909) and Chiloango (Boulenger, 1912a) river basins. These specimens were revised, and according to Géry & Mahnert (1977), those from the Ogowe River would be Alestopetersius and those from Chiloango would be Nannopetersius (see Paugy, 1986). Finally, recent studies (Paugy & Schaefer, 2007) show that B. intermedius must be considered as Lower Guinean endemic species found in the Cross, Kribi (=Kienké), Ogowe and Nyanga basins) (see also Faunafri).
This species has a wide distribution, with no known major widespread threats. It is therefore listed as Least Concern.
There is no information available on threats to this species.
Bibliography
Brycinus jacksonii (Boulenger, 1912)
Type and type locality
Alestes jacksonii Boulenger, 1912: 601. Type locality: “Malawa River, Kavirondo, 4000 feet”, holotype BMNH n° 1912.10.15:6.
Synonyms
Alestes nurse (partim) Boulenger, 1907
Alestes jacksonii Boulenger, 1912
Brycinus jacksonii Myers, 1929
Alestes jacksoni Greenwood, 1959
Brycinus jacksoni Géry, 1968
Common names
English: Victoria robber (Kenya, Rwanda)
Estonian: Victoria kardsalmler
Luo: Soga (Kenya)
Luyia: Nsoga (Kenya)
Not specified: Nsoga (Uganda)
Rwanda: Ikiraba/Inshoga (Rwanda)
Swahili: Mtera (Tanzania), Osoga (Kenya, Tanzania), Soga ‘(Tanzania)
Description
Diagnosis: adipose eyelid rudimentary and fronto-parietal fontanel absent in adults. In juveniles the fontanel measures approximately 1 mm and separates the two frontal bones. Gill rakers are thin and rather short. Pectoral-fins are long and reach ventral-fins. In males, there is a sexual dimorphism affecting anal-fin shape.
Measurements and counts of the original description, and those of holotype revised, of nine specimens from the Lake Victoria and of 21 specimens examined by Greenwwod (1959d).
Brycinus jacksonii: main morphological characters of types and additional material (* total length, ** scales between lateral line and ventral insertion)
Maximum reported size: 270 mm SL (male).
Colour: humeral spot is weak but the precaudal clavate blotch, well marked, extends backward on median caudal-fin rays. According to Greenwood (1959d) alive specimens are: “(Known only for specimens from Lake Victoria and the Victoria Nile ) Dorsale surface bluish-grey to bluish-black, mutedly iridescent silver ; (...). Dorsale fin grey, anal and pectoral fins fainly yellow or yellowish-orange, caudal yellow or yellowish-orange, adipose dorsal orange. I cannot confirm Degen's description (cited by Boulenger, 1907a, p. 123 of the clavate peduncular blotch as being" brilliant orange in life"; possibly Degen has confused the adipose dorsal with this blotch.”
Affinities: B. jacksonii is close to B. nurse with which it is often confused with. See below the results of the analysis carried out on 13 different populations.
Dendrogramm showing relationship between different population of B. jacksonii and B. nurse. Taxonomic distances based on 7 characters.
There are weak differences between B. nurse specimens from Sudan or Nilotic basins and those from coastal basins of Benin or Togo. In the same way there is a tiny distance between the holotype of B. jacksonii and specimens from the Lake Victoria. On the other hand the difference is high between the B. jacksonii group and the B. nurse group. Thus, as suggested by Greenwood (1959d), it seems that B. nurse does not exist in the Lake Victoria in which it is replaced by B. jacksonii. Except the allopatry, we can distinguish the two species on the basis of two essential characters: in B. nurse the anal branched rays number is comprised between 10 and 15 (generally 12 or 13), whereas in B. jacksonii this number is higher, 14 to 16. Moreover, in B. jacksonii the snout is shorter than that of B. nurse (respectively comprised 3.7-4.1 vs 2.8-3.6 in length of head). Finally if B. nurse has always 5½ scales above the lateral line, B. jacksonii has sometimes 4½ scales above the lateral line.
Reproduction
Information concerning the reproduction of B. jacksonii is weak, but Greenwood (1959d) thinks that the reproduction takes place during the rainy season and that the individuals spawn in the rivers during the flood.
Diet
B. jacksonii must be considered as omnivorous because remains of aquatic plants, terrestrial and aquatic insects, molluscs (scarce) and fish are found in stomach contents (Graham, 1929; Greenwood, 1959d). In a thorough study Corbet (1961) confirms this eclecticism, but estimates that the species feeds mainly leaves of aquatic plants. When this type of food is scarce, the species eats insects which are gulped down from the surface (aquatic nymphs or imagos and terrestrial insects), in relation with the moon rhythm and the emergences of aquatic insects which take place during the new and the full moon.
Brycinus jacksonii: diet composition in relation with the lunar cycle. x axis: lunar month (6 phasis); y axis: % occurrence (variable scale).
Habitat
In the Lake Victoria, B. jacksonii is generally found along the littoral shore. But it is not a strictly lacustrine species because B. jacksonii is also abundant in the Victoria Nile between the Lake Kyoga and the Owen Falls.
Brycinus jacksonii is found in inshore areas of lakes and quiet parts of rivers. In Lake Victoria it is confined to shallow coastal areas (Greenwood 1959d; van Oijen 1995), in water less than 20 m deep (Corbet 1961, van Oijen 1995). The Victoria Robber is known to run up rivers and streams in Lake Victoria during the rainy season (Greenwood 1966).
Distribution
B. jacksonii is endemic in the upper Nile (Victoria Nile), in the Lake Victoria (and some tributaries) and in the Lake Nabugabo). Middle Akagera system records of B. nurse and B. imberi must be refered to B. jacksonii (De Vos et al., 2001) (see also Faunafri).
Brycinus jacksonii occurs in Lake Victoria, Lake Nabugabo, the Victoria Nile, the Malawa River (Kyoga system) and the Middle Akagera drainage. There is no recorded decline in the species in recent years and it is relatively widespread and abundant in parts of its range. This species may be locally threatened by increasing water turbidity, eutrophication and fishing. The Victoria Robber is therefore listed as Least Concern.
Possible threats include increased water turbidity and siltation, as a consequence of erosion and farming extension on the watersheds and floodplains, eutrophication, loss of riverine migratory routes, fishing pressure and illegal fishing practices.
Bibliography
Brycinus kingsleyae (Günther, 1896)
Type and type locality
Alestes kingsleyae Günther, 1896: 279. Type locality: “Ogowe River”, syntypes BMNH n° 1896.5.5:77-80.
Synonyms
Alestes kingsleyae Günther, 1896
Brycinus kingsleyae Myers, 1929
Myletes kingsleyae Poll, 1976
Common names
: Kingsley kardsalmler
Fang: Mbara (Gabon)
French: Tétra africain (Gabon)
Description
Diagnosis: fronto-parietal fontanel present in very small individuals, disappearing with growth. Gill rakers are thin and rather short. Body with a prominent humeral spot on the third post-opercular scale. 8 outer premaxillary teeth aligned in a single row. Scale formula: 4½/24-30/3½. Anal fin rays III-11-13. This species exhibits sexual dimorphism of the anal fin shape in adult males.
Measurements and counts of the original description, and those of two syntypes revised, of eight specimens from the Ogowe River and of six specimens from the Loémé River.
Brycinus kingsleyae: main morphological characters of types and additional material.
Maximum reported size: 166 mm SL (male).
Colour: body with a distinct black longitudinal band extending from middle of rayed dorsal fin to the adipose fin (situated dorsal to the median rays of caudal fin). The band is wider anteriorly than posteriorly, anteriorly it is about one scale wide. In preserved material, the fins are generally greyish; in life, Boulenger (1912a) writes: “Nageoires tantôt jaunes, tantôt oranges; adipeuse parfois d'un rouge vif” (fins sometimes yellow, sometimes orange; adipose fin sometimes bright red).
Affinities: B. kinsleyae is close to B. taeniurus and B. opisthotaenia. Body with a clearly wider band than the former.
For a long time, there was confusion between B. kingsleyae and B. opisthotaenia. But a morphological study of these two species showed that some characters and the color pattern clearly separate these putative species (Kamdem Toham & Teugels, 1997). B. kingsleyae consistently displayed a lateral black band that does not reach the vertical of the posterior base of the dorsal fin. Conversely, B. opisthotaenia showed a lateral black band that extend from at least the vertical of the posterior dorsal fin to the middle caudal fin rays (see fifure below).
Color patterns in B. kingsleyae (left) and B. opisthotaenia (right) based on 10 specimens. The blue vertical line marks the vertical of the posterior dorsal fin and allows distinguishing the two species.
The existence of two species based on their difference in colour pattern is confirmed by some morphometric data. Thus, the diameter of the eye is significantly smaller in B. kingsleyae and the pelvic and pectoral fins, are significantly longer in B. opisthotaenia. The existence of two species is further supported by meristic counts, especially the number of anal branched rays. Altough, an interbasin variation was observed for this character, the median values of both species are significantly different (Kamdem Toham & Teugels, 1997).
Distribution
B. kingsleyae was described from the Ogowe basin in Gabon. Found also in the Sanaga, Nyong and Ntem basins in Cameroon, Nyanga basin in Gabon, Loémé and Kouilou basins in Congo, Chiloango basin in Cabinda (Angola). The species occurres also in the congolese basin, especially in lower and upper tributaries courses (Kasaï, Ubangi-Uele, Lualaba, Luapula-Mweru). Reported by Borodin (1936) from the Lake Tanganyika, but its presence in this area is certainly dubious (Poll, 1946) (see also Faunafri).
The species is widespread, without major threats throughout central Africa and is assessed as Least Concern.
Major threats: none known.
Bibliography
Brycinus lateralis (Boulenger, 1900)
Types and type localities
Alestes lateralis Boulenger, 1900: 130. Type locality: “Lac Dilolo, Katanga”, syntypes MRAC n° 384-388.
Alestes natalensis Boulenger, 1904: 155. Type locality: “Natal, near Durban”, syntypes BMNH n° 1904.6.28.33.
Alestes thamalakanensis Fowler, 1935: 257-258. Type locality: “Thamalakane River at Maun”, holotype TM n° 15233.1033, paratypes TM n° 15233.1115-1119,1122,1124,1126-1128,903,945-946,1032,1034-1041,1043-1044,964.
Alestes langi Fowler, 1935: 258-259. Type locality: “Thamalakane River at Maun”, holotype TM n° 15259.1042, paratypes TM n° 15259.1114, 1120-1121,1125,1129,1031,1056-1059.
Petersius maunensis Fowler, 1935: 258-259. Type locality: “Thamalakane River at Maun”, holotype TM n° 15276.946, paratypes TM n° 15256.950.
Synonyms
Alestes lateralis Boulenger, 1900
Alestes natalensis Boulenger, 1904
Alestes thamalakanensis Fowler, 1935
Alestes langi Fowler, 1935
Petersius maunensis Fowler, 1935
Alestes (Alestiops) lateralis Hoedeman, 1951
Rhabdalestes maunensis Poll, 1967
Myletes lateralis Poll, 1976
Common names
Afrikaans: Mbala/Streep-rower (Namibia), Streep-rower (South Africa)
Bemba: Nchenga/Tala (Zambia)
English: Stripped Robber (Namibia, South Africa, Zambia, Zimbabwe), Stripe-tailed Robber (Zambia)
Estonian Triip-kardsalmler
Lwena: Mungumba (Angola)
Nyanja: Tsimbu (Malawi)
Description
Diagnosis: a little size species with a rudimentary adipose eyelid, but iwth a well developed fronto-parietal fontanel. Gill rakers are thin and long. Humeral spot is absent. Flanks with a distinct blackish band, lighter anteriorly, darker posteriorly. On the caudal peduncle there is a prominent black blotch extending onto the mledian rays of the caudal-fin to the margin of the caudal fork. . 8 outer premaxillary teeth aligned in a single row. Scale formula: 5 ½/27-37/3½. Anal fin rays III-14-17. This species exhibits sexual dimorphism of the anal fin shape in adult males. Because of this dimorphism, Fowler (1935) described each sex as a different species: A. thamalakanensis for females and A. langi for males. Finally he described juveniles as a third species, Petersius maunensis.
Measurements and counts of the original description, and those of five syntypes revised, of three specimens from Katanga, of nine specimens of Lake Kariba and of 13 specimens from Lake Calundo, Angola (Poll, 1967b).
Brycinus lateralis: main morphological characters of types and additional material.
Maximum reported size: 140 mm SL (male).
Colour: humeral spot is absent. Flanks with a distinct blackish band, lighter anteriorly, darker posteriorly. On the caudal peduncle there is a prominent black blotch extending onto the mledian rays of the caudal-fin to the margin of the caudal fork. Flanks silvery, back greenish and belly whitish. Paired fins seem to be hyaline and impaired fins greyish. There is a brownish spot on the opercular cover.
Affinities: B. lateralis is close to all small sized Brycinus. But some characteristics are particular to this species. Eight outer premaxillary teeth in B. lateralis vs. six for B. leuciscus, B. bartoni, B. longipinnis, B. derhami, B. intermedius and B. tholloni. B. lateralis has a higher number of scales above lateral line than B. humilis (5½ vs 4½), a higher number of gill rakers than B. tessmanni (18-22 vs 16-17) and a lower number of predorsal scales than B. sadleri (11-11½ vs 12½-14). In B. lateralis, insertion of the dorsal fin is more or less above that of the ventrals. In B. sadleri, insertion of the dorsal fin is well behind that of the ventrals. Finally, the global distribution of B. lateralis is different from that of the other species.
Growth
In Lake Kariba growth of the females is faster than that of the males (Balon, 1971), as it is generally a rule for Alestes s.l. After the original data we have computed the different parameters of the growth curve:
Nevertheless, this results must be accepted with precaution because the MRS (122 mm SL) given by the author is clearly lesser than the calculated L ∞. That is probably due to a overestimation of the growth curve.
Brycinus lateralis: growth in Lake Kariba (MRS: maximum reported size).
Reproduction
According to Bell-Cross (1976) B. lateralis executes anadromous migration during the spawning period, at the beginning of the rainy season. In the upper Zambezi, individuals migrate between the rivers and the floodplains (van der Waal, 1996). In the Lake Kariba, spawning takes place in immerged vegetation, particularly in roots of Salvinia (Balon, 1971). According to this author these favourable conditions could explain the proliferation of B. lateralis at the expense of B. imberi which has more riverine habits. Particularly B. imberi does not found the necessary alternation flood-low water for its reproduction. In Lake Kariba and Kafue, the mean fecundity of 39 specimens between 20-60 mm SL is approximately 260 eggs by female (Balon & Coche, 1974). That corresponds to a relative fecundity rising 260,000 eggs per kg. For 62 larger specimens (70-140 mm SL) the mean fecundity is approximately 4,900 eggs, such as 170,000 eggs per kg. This later value is near that generally observed for most part of Alestiini.
Diet
B. lateralis is generally considered as omnivorous (Bell-Cross, 1976) with live preys preferences (Jackson , 1961a).
Like other alestiins, B. lateralis is an opportunistic omnivore, but feeds primarly on crustacean zooplankton and insect larvae, as well as a variety of other items in Lake Kariba (see table below) (Mitchell, 1976).
Brycinus lateralis: diet (% occurrence) in Lake Kariba (Mitchell, 1976).
Populations
In spite of the large distribution of the species, all the populations have more or less homogeneous merictics characters.
Brycinus lateralis: number of anal fin rays.
Brycinus lateralis: number of lateral line scales.
Brycinus lateralis: number of gill rakers on the first lower limb.
Distribution
The distribution of B. lateralis, limited between 5° and 25° South latitude, is rather discontinuous. In the Congolese system, B. lateralis seems to be limited in the higher courses of the streams: Kasaï, Katanga and Luapula-Mweru. More in the south it is distributed in Angola (Cunene and Cubango), Botswana (Cubango-Okavango), Zambia, Zimbabwe, Mozambique, South Afica (Natal) and Swatziland. On a strictly geographical point of view, B. lateralis seems to have a more or less continuous distribution, but on a hydrological point of view the distribution of the species seems to be a patchwork because it is generally restricted to the upper courses. For example, the colonisation of the middle Zambezi follows the damming of the river. Before the closure of the Kariba dam, B. imberi inhabited the middle Zambezi. After the creation of the lake, B. lateralis, better adapted to the lacustrine conditions seems to have replaced B. imberi. Moreover, if these two species can be sympatric, they scarcely cohabit and when B. lateralis is distributed all along the basin, B. imberi is absent (Cunene, Okavango-Cubango). It is generally admitted that there is a niche overlapping between the two species and that there is certainly a reciprocal exclusion. Finally, the large distribution of B. lateralis in the southern tropical region supposes certainly ancestral connections between Zambezi and Congo (Kasaï) via Okavango swamps (see also Faunafri).
This species has a wide distribution, with no known major widespread threats. It is therefore listed as Least Concern. It has also been assessed regionally as Least Concern for central and southern Africa. In the east Africa regional assessment it has been categorised as Vulnerable (VU D2) as it only occurs in the Lower Shire River in Malawi where the threats to habitat due to increased sedimentation has the potential to impact on the spawning success of the whole population.
Major threats: for the majority of its distribution there are no known threats to this species, however sedimentation in rivers poses a threat to populations in Lower Shire River in Malawi.
Bibliography
Brycinus leuciscus (Günther, 1867)
Types and type localities
Alestes leuciscus Günther, 1867: 114. Type locality: “Niger”, syntypes BMNH n° 1865.1.80:16-17.
Alestes senegalensis Steindachner, 1870: 545-546. Type locality: “Senegal”, syntypes NMW n° 66741, 66774-66816, 66824, 66895, 67147, 69610.
Alestes nurse albolineatus Holly, 1928: 312. Type locality: “Senegal”, syntypes NMW n° 13113.35.
Alestes nigrilineatus Svensson, 1933: 53-56. Type locality: “Gambia River”, syntypes NRMS n° 16222.
Synonyms
Alestes leuciscus Günther, 1867
Alestes senegalensis Steindachner, 1870
Alestes nurse (non Rüppel) Boulenger, 1909
Alestes nurse senegalensis Holly, 1928
Alestes nurse albolineatus Holly, 1928
Alestes nigrilineatus Svensson, 1933
Brycinus leuciscus Géry, 1968
Alestes leuciscus senegalensis Reizer, Mattei & Chevalier, 1972
Common names
Bambara: Tinèni (Mali)
Estonian: Valev kardsalmler
Ewe: Simegbogboe (Ghana)
Finnish: Säynealesti/Siniraitatetra
Fulfulde, Pulaar: Anndoonde (Senegal)
German: Afrkanischer Weißfischsalmler
Hausa: Kawara (Nigeria)
Kanuri: Kaya (Nigeria)
Kim: Haï/Han (Chad)
Nupe: Egbagi (Nigeria)
Soninké: Wandoone (Senegal)
Wolof: Dabé (Senegal)
Yoruba: Ajarapo (Nigeria)
Description
Diagnosis: parietal fontanel always present, even in adults. Dorsal fin origin at about the same level as pelvic fin insertions. Jaws equal; the six premaxillary teeth aligned in a single row. Scale formula: 5½/26-31/3½. Anal fin with three spines and 13-17 branched rays. Lower (ceratobranchial) limb of first gill arch with 16-19 short gill rakers. This species shows sexual dimorphism affecting the anal-fin shape in adult males.
Measurements and counts of the original description, and those of one syntype and syntypes of A. nigrilineatus revised, of specimens from Benue (8), Volta (10 and Niger (6) Rivers.
Brycinus leuciscus: main morphological characters of types and additional material.
Maximum reported size: 119 mm SL.
Colour: body with a black humeral spot as well as a “claviform” black blotch on caudal peduncle, the latter extending to hind margin of caudal-fin fork. Back greyish-green, sides silvery, belly white. All fins yellow; upper part of eye equally yellow. A dark longitudinal band below lateral line, better visible in formalin-preserved specimens.
Affinities: often confused with B. nurse, but distinguished from that species by having only six teeth in the outer premaxillary row (eight in B. nurse), and a parietal fontanel that remains open in adults (closed in adults of B. nurse); also the colouration of the fins is different in these species. B. leuciscus is more closely related to B. longipinnis, but has more lower gill rakers (16-19 against 12-15). Another related species is B. luteus which is endemic to the upper Volta basins, but has much longer gill rakers.
Growth
In Niger River, this small-sized species does not exceed two years, because specimens with two annuli have never been captured (Daget, 1952; Daget, 1954 and Daget, 1957). Spawning takes place in August, after the growth of juveniles is very fast during the flood, then stops during approximately eight months (December to August) during low water. Then fish reach their second year and have again a fast growth until December. After, at the beginning of the low water a second stop of growth takes place. Finally, they probably die at the end of their second reproduction cycle.
Brycinus leuciscus: growth in Niger River.
Reproduction
In Niger River, sexual maturity of B. leuciscus is reached at the end of the first year (Daget, 1952). The number of eggs is closely related to the size of the females and the smallest have no ripe ovocytes. The spawning period takes place at the end of the July or at the beginning of August, i.e. during the flood. For first year individuals the fecundity is about from 1,000 to 1,100 eggs per female, but can reach 3,500 to 4,000 in second year females.
Diet
In the Middle Niger basin, during the flood, B. leuciscus feed mainly on seeds and insects but eat also grass. During the low water, the alone available food seems to be phytoplankton. During the flood, the species constitutes large reserve of grease. It is at that time that local fishermen use tineni (local name of B. leuciscus) to extract oil whose the rate can exceed 25% of the body weight.
Populations
In spite of the large distribution of the species in numerous sudan basins, all the populations have more or less homogeneous merictics characters.
Brycinus leuciscus: number of anal fin rays.
Brycinus leuciscus: number of lateral line scales (*: plus 1 or 2 scales).
Brycinus leuciscus: number of vertebrae.
Migrations
In Niger River, B. leuciscus migrate up forming extensive shoals during moonlit night. Local fishermen know this migratory habits and they fish during this moonlight period to get high catch levels. During this upstream migration fishes swim approximately 9 km per day. The shoals dissociate when there is no moon then they migrate up again when the new lunar cycle begins. It seems that this phenomenon, go and stop, is particular to this species. These migrations take place at the beginning of the low water when fishes leave floodplains for the main channel (Daget, 1949; Daget, 1952; Daget, 1954 and Daget, 1957).
Distribution
Basins of the Volta, Niger including the Benue, Senegal, Gambia, Tomine (Corubal) and Casamance. Therefore it is a Sudan species absent in Chad and Nile River basins (see also Faunafri).
This species is widespread with no known major widespread threats.
Major threats: there is a potential threats are localised, mainly deforestation (sedimentation) due to bad agricultural practices.
Bibliography
Brycinus longipinnis (Günther, 1864)
Types and type localities
Brachyalestes longipinnis Günther, 1864: 315. Type locality: “Sierra Leone”, syntypes BMNH n° 1864.3.16:2-7.
Alestes chaperi Sauvage, 1882: 330. Type locality: “Efirou, rivière Cania”, syntypes MNHN n° A.4418-4423.
Brycinus longipinnis bagbeensis Géry & Mahnert, 1977: 627. Type locality: “Bagbé River, Sierra Leone”, holotype and paratypes BMNH n° 1932.5.18:6-11.
Synonyms
Brachyalestes longipinnis Günther, 1864
Alestes longipinnis Hubrecht, 1881
Alestes chaperi Sauvage, 1882
Alestes (Brachyalestes) longipinnis Steindachner, 1894
Brycinus longipinnis Fowler, 1936
Bryconalestes longipinnis longipinnis Hoedeman, 1951
Bryconalestes longipinnis chaperi Hoedeman, 1951
Brycinus chaperi Géry, 1968
Brycinus longipinnis bagbeensis Géry & Mahnert, 1977
Common names
Danish: Langfinnet congotetra
English: African long-finned tetra/African longfin (USA), African longfin tetra (Nigeria), African tetra (Australia, Cameroon), Characin (Ghana), Long finned characin (USA), Longfin tetra (USA, global), Silverd)sides (Ghana)
Estonian: Pikkuim/Pikkuim-kardsalmler
Ewe: Morganutewoe/Wuganutewoe (Ghana)
Fang: Abat (Equatorial Guinea)
Finnish: Pikkuviirialesti/Pikkuviiritetra/Viirialesti/Viiritetra
Ga: Tewe kpiti (Ghana)
German: Afrikanischer Langflossensalmler/Langflossensalmler
Hausa: Kawara (Nigeria)
Ijo: Ebiniipe (Nigeria)
Kanuri: Kaya (Nigeria)
Krio: Kartei/Kay-ray-day/Serekulay (Sierra Leone)
Limba, west-central: Kay-ray-day (Sierra Leone)
Mende: Kartei (Sierra Leone)
Nupe: Egbagi (Nigeria)
Polish: Alestes chapera
Themne: Serekulay (Sierra Leone)
Yoruba: Ajarapo (Nigeria)
Description
Diagnosis: fronto-parietal fontanel always present, even in adults. Dorsal fin origin at about the same level as pelvic fin insertion. Adipose eyelid rudimentary. Jaws equal; the 6 outer premaxillary teeth aligned in a single row. Scale formula: 5½/25-34/3½. Anal fin III-15-23. Lower (ceratobranchial) limb of first gill arch with 13-15 thin and short gill rakers. Sexual dimorphism of anal fin shape in adult males which also have the first rays of dorsal and pelvic fins ray filamentous, the dorsal filament extending beyond the adipose fin, and the pelvic filament reaching to anal fin, when pressed to body. Finally, in sexually mature males, body depth increases with growth at a faster rate than in females.
Measurements and counts of the original description, and those of two syntypes, of syntypes of B. chaperi and of 12 syntypes revised
Brycinus longipinnis: main morphological characters of types.
Maximum reported size: 101 mm SL.
Colour: body with a humeral spot, as well as a broad precaudal band, the latter extending over the entire length of caudal peduncle and continuing backwards on median caudal fin rays to the hind margin of caudal fork. Ground colour silvery, back greenish, belly white. In adult males, unpaired fins and sometimes also pelvic fin filaments, violet-red. Females with pale orange fins, and a rather distinct yellow blotch on each caudal fin lobe. Finally, adult males have a bright red spot above eye which in females is orange-coloured.
Affinities: B. longipinnis is close to B. tholloni, B. intermedius, B. sadleri, B. tesmanni and B. derhami, but has less scales above lateral line than the four formers (5½ vs 6½). It can be easily distinguished from B. derhami by the shape of the peduncular blotch (long and froad in B. longipinnis vs ovoid and short in B. derhami).
Shape of the precaudal blotch in Brycinus longipinnis and B. derhami.
Growth: concerning the length-weight relationship and the coefficient of condition, le slope of the relation logW = b logSL + loga is higher for males than for females. Furthermore for the males, this slope is always significantly different of 3 (Paugy, 1982a). In males the condition increases faster than in females because body height is higher in males than in females.
Reproduction
In all streams of Côte d'Ivoire, there are always individuals at different maturity stages (Paugy, 1982a). In males and females the sexual maturity is reached during the first year of life. According to the basins, the fecundity seems different (see below).
Brycinus longipinnis: relative fecundity (F) in two rivers of Côte d’Ivoire (SL: standard length; W: body weigth; GW: gonad weigth).
According to these relations, the relative fecundity reaches 156,000 and 97,000 in Bandama and Cavally respectively. These values are rather lesser than that found for the other Brycinus species in Côte d'Ivoire.
Diet
In Côte d'Ivoire, B. longipinnis feeds on terrestrial and aquatic insects (Planquette & Lemasson, 1975).
Populations
In spite of the large distribution of the species, all the populations have more or less homogeneous merictics. Nevertheless comparing metric characters two groups may be defined: a Western African group and a Central African group (Paugy, 1982a). This polytypic species is not only polymorph and its biological features present a wide variation according to the biotopes and the geographical area.
Brycinus longipinnis: number of anal fin rays.
Brycinus leuciscus: number of lateral line scales (*: plus 1 or 2 scales).
Brycinus leuciscus: number of vertebrae.
Distribution
B. longipinnis is distributed along the entire Atlantic coastal fringe, from Gambia to Congo. B. longipinnis is a Guinean form. According to Thys van den Audenaerde (1968), the species is originating from the Western forest massif. It is generally found in the upper as well as the lower river courses and may even occur in brackish waters of estuarine areas. This is the only Brycinus species that also inhabits the smaller water courses, but specimens from these streams are always smaller than those taken in large rivers (see also Faunafri).
This species has a wide distribution, with no known major widespread threats. It is therefore listed as Least Concern. It has also been assessed regionally as Least Concern for central and western Africa.
Major threats: none known.
Bibliography
Type and type locality
Alestes luteus Roman, 1966: 63-65. Type locality: “Kou, affluent de la Volta Noire à 30 km au nord de Bobo Dioulasso (Haute Volta)”, holotype MRAC n° 141128, paratypes MRAC n° 141129-141133, 141134-141141, 141142-141144.
Synonyms
Alestes luteus Roman, 1966
Brycinus luteus Géry & Mahnert, 1977
Common names
Estonian: Kollane kardsalmler
Description
Diagnosis: fronto-parietal fontanel always present, even in adults. Dorsal fin origin at about the same level as pelvic fin insertions. Jaws equal; the six outer premaxillary teeth aligned in a single row. Scale formula: 5½/25-31/3½. Anal fin with three spines and 15-16 branched rays. Lower (ceratobranchial) limb of first gill arch with 16 or 17 long gill rakers. This species shows a sexual dimorphism affecting the anal-fin shape in adult males.
Measurements and counts of the original description, and those of holoype revised, of 16 specimens of the Volta river studied by Roman (1966) and of 9 specimens of the Volta River basin.
Brycinus luteus: main morphological characters of types and additional material (* plus 1 or 2 scales at the base of the caudal-fin).
Maximum reported size: 76 mm SL.
Colour: body with a humeral spot and a precaudal blotch, the latter extending to hind margin of caudal-fin fork. Ground colour silvery, back dark yellowish, belly white. Fins yellowish, except for the pectoral and pelvic fins which are colourless. These colours disappear after preservation in alcohol, but a dark band running on sides from gill cover to caudal fin and broadening at about mid-length of body becomes more apparent.
Affinities: B. luteus is close to B. leuciscus, but at the same size, body depth of B. luteus is slightly lesser (SL/depth>3) than that of B. leuciscus (SL/depth <3). The number of gill rakers is rather the same, but in B. luteus they are longer than in B. leuciscus.
Distribution
B. luteus is only known from the upper Volta basin (see also Faunafri).
This species is only known from the Upper Volta basins in Burkina Faso (Mouhoun, Bougouriba - Black Volta and the Nakambe - White Volta), with an AOO of less than 2,000km2 and known from five locations. Little is known about the population of this species, but it is probably limited by the availability of its preferred habitat as it requires high quality water. It is vulnerable to any future decline in water quality from pollution and is potentially threatened by drought.
Major threats: this species is threatened by drought leading to the reduction of the flows and currents, and water pollution.
Bibliography
Brycinus macrolepidotus Valenciennes, 1850
Types and type localities
Brycinus macrolepidotus Valenciennes, 1849: 157. Type locality: “Sénégal”, holotype MNHN n° 6335.
Alestes rutilus Boulenger, 1916: 181. Type locality: “N. Sherbo, Sierra Leone”, syntypes BMNH n° 1915.4.13:16-17.
Synonyms
Brycinus macrolepidotus Valenciennes, 1849
Alestes macrolepidotus Bilharz, 1852
Alestes rutilus Boulenger, 1916
Brycinus rutilus Myers, 1929
Brycinus macrolepidotus macrolepidotus Hoedeman, 1951
Common names
Adangme: Dzaplapa (Ghana)
Arabic: Kawara safsaf/Kawwara safsaf (Sudan)
Baoulé: Katô/N’gba (Cote d'Ivoire)
Dinka, Northeastern: Alerio/Cin/Melek (Sudan)
English: Characin (Ghana), Large scaled robber, Silversides (Kenya), True big-scale tetra (USA)
Estonian: Suursoom-kardsalmler
Ewe: Dzaflafa (Ghana)
Finnish: Ruohotetra/Suurisuomualesti
Ga: Dzaplapa (Ghana)
German: Großschuppiger Brycinus
Guro: Zoglou (Cote d'Ivoire)
Hausa: Anto/Barga/Kakara (Nigeria)
Ijo: Elei (Nigeria)
Jula: Farabanin (Burkina Faso)
Kele: Lilongo/Walo (Democratic Republic of Congo)
Kim: Adjamdjer/Adjamdjor/Gamle/Kadjianre (Chad)
Lombo: Walo (Democratic Republic of Congo)
Mòoré: Tatare (Burkina Faso)
Nuer: Leggani (Sudan)
Shilluk: Agamikak (Sudan)
So: Walo (Democratic Republic of Congo)
Wolof: Dabé (Senegal)
Zande: Gbagara (Sudan)
Description
Diagnosis: fronto-parietal fontanel never present, even in juveniles. Dorsal fin origin behind level of pelvic fin insertion. Number of outer premaxillary teeth 8-14, two of which shift progressively backwards with growth; supraorbital bone rather well-developed; upper jaw prominent in adults. Scale formula: 4½/21-31/3½. Anal fin rays III-10-16. Gill rakers on lower limb of first arch 14-22. This species exhibits no sexual dimorphism of anal fin shape in adult males.
Measurements and counts limits are given below:
Brycinus macrolepidotus: main morphological for all populations examined
Maximum reported size: 530 mm SL.
Colour: body with a humeral spot and a black precaudal blotch, the latter extending partly onto the median caudal fin rays. Back greenish, belly white; sides sometimes with a broad dark longitudinal band running from gill cover to caudal fin. This colour pattern occurs only in adults but does not seem to be correlated with sexual activity. In most fish the fins coloration varies from orange-red or pink to grey; only live specimens from the Cavally river (Côte d'Ivoire) have vermilion red fins. In some populations the fin margins are trimmed with dark pigment. Young individuals have a white spot on upper side of caudal peduncle.
Affinities: B. macrolepidotus is close to all other species of the macrolepidotus group. Nevertheless in B. poptae, B. carmesinus, B. grandisquamis and B. schoutedeni the supra-orbital bone is more developed and the number of anal fin branched rays is less numerous (9-12 vs 11-16). In B. macrolepidotus there are more scales below the lateral line than in B. rhodopleura (3½ vs. 2½), the body depth is lesser than in B. brevis (SL/BD>3 vs SL/BD<3). Finally in B. batesii upper and lower jaws are more or less equal whereas in adults B. macrolepidotus maxillary exceeds the lower jaw. Moreover in B. batesii there are more lateral line scales (29-31) than in B. macrolepidotus (21-28).
Remarks: four species, with limited distribution) are very close to B. macrolepidotus: B. batesii (Cameroon), B. brevis (some coastal rivers in Ghana and Nigeria), B. rhoddopleura (Lake Tanganyika) and B. schoutedeni (South Cameroon to Congo). A study in progress indicates that these species have characters which exhibit a clinal geographic variation. Similar, clinal variation was already observed in West Africa (Paugy, 1982 b). In anticipation of the conclusions of the ongoing study, B. macrolepidotus is generally considered the only species of this group present in Africa.
Growth
In Côte d'Ivoire, the alone results are based on fishes reared in ponds (Paugy, 1982b). They are only indicative and cannot be extrapolated to natural condition although no artificial food was given to the individuals.
Brycinus macrolepidotus: length growth (fish reared in ponds).
Reproduction
In Côte d'Ivoire B. macrolepidotus reaches sexual maturity at respectively 175 mm SL and 185 mm SL for males and females, that is to say probably at the end of their second year (Paugy, 1982b). Other works seem to confirm this observation (Roest, 1974; Planquette & Lemasson, 1975) because the first maturity size is estimated at 180 mm SL. The species has no very well defined breeding season. Nevertheless, a smaller proportion of fish seems to be mature from November to February. In other geographical areas, particularly in the Sahelo-Sudan province all the fish breed at the same time. Thus, spawning takes place during the flood in the Niger and Senegal basins (Daget, 1954; Reizer et al., 1972) or during the low water in the Chad basin (Blache et al., 1964). In these very contrasted climatic regions the seasonal timing of reproduction is under the influence of hydrological conditions and the alternation of low and high waters. This hydrological alternation is weaker in the Guinean region and does not control the reproduction cycle. However, it is possible that the hydrological conditions are not the direct cause but that they had an influence on the food availabilities which would be the real regulator of the eggs maturity.
Planquette & Lemasson (1975) noted that during low water there were large fish gatherings where not very deep water and especially when there are Vallisneria. Two field observations in the Maraoué (Bandama basin) and Léraba (Comoé basin) made possible to describe the reproduction behaviour in Côte d'Ivoire. Schools of adults stay along covered moss rocks and strike them with their caudal peduncle and deposit their gametes. Pelagic eggs are free in the moss just under the surface of water. Fish seem to be in a collective frenzy but remain wary and flee if appears a danger. However this escape is not definitive and they take again their evolutions shortly after. In the Léraba River collective spawning was observed from midday to the night. The next morning fish continued their game but we do not know if their activity has continued all during the night. Samples of eggs during this period show that their diameter doubles in contact with water and reaches an average 2.3 mm (1.2 mm for eggs sampled in a female 5). In Côte d'Ivoire B. macrolepidotus can be considered as a high fecundity species. The relative fecundity is estimated between 180,000 (Paugy, 1982b) and 184,000 (Albaret, 1982) eggs/kg. See below relations of fecundity (F) with length (SL), weight (W) and gonad weight (GW):
Brycinus macrolepidotus: fecundity (F) in relation with length (SL), body weight (W) and gonad weight (GW). Data recorded in Côte d’Ivoire.
Diet
All observations show that B. macrolepidotus is omnivorous but prefer to feed on exogenous items. For feeding, they swim along the banks just under the surface, and eat insects, fruits or leaves which fall in water. For this surface swimming, the species is adapted and its caudal-fin has a more developed lower lobe. In others Alestids, the two lobes are generally equal. See below a synthesis of the B. macrolepidotus diet in different regions of Africa.
Brycinus macrolepidotus: diet in different regions of Africa.
In the archipelago of Lake Chad Brycinus macrolepidotus, a primary consumer, is the dominant macrophyte-consuming fish (macrophytes forming 100 % OC, 59 % V) with a preference for young leaves of Potamogeton and Ceratophyllum, that fish graze on the surface. Macrophytes are represented by a low proportion of seeds and a large fraction of leaves. However, insects, particularly terrestrial, are also important in the diet, mainly during the flood (see table and figure below). Obviously, this propensity to evolve near the surface gives, to this species, great opportunities to catch the insects fallen in the water.
Brycinus macrolepidotus: diet in the Lake Chad archipelago (% C: occurrence percentage; (% V:.volumetric percentage; F.I.: feeding index) (from Lauzanne, 1976).
Brycinus macrolepidotus: diet in the Lake Chad archipelago. The percentage of occurrence is put on the upper radius of the sector and the volumetric percentage on the lower one. The area of parallelogram is proportional to the food index (redrawn from Lauzanne, 1976).
B. macrolepidotus does not seem to have a particular predilection for a given group of insects, because the species catches all the preys present, even hymenoptera like bees. Aquatic insects are mainly chironomid's imagos, very dominant, and some mayflies as Povilla adusta (see table below).
Brycinus macrolepidotus insects in the diet (flood and low water) in the Lake Chad archipelago (from Lauzanne, 1976).
Populations
B. macrolepidotus morphology shows high variations according to the regions (Paugy, 1982b) and it is possible to distinguish three populations types. Populations found in a large geographical area which have stable characters (Sudan-Sahelo; Nile and Congo basins) populations, very different from the former, which inhabit very narrow area but have homogeneous characters (Guinea, Sierra Leone and Western Liberia) and finally populations which have heterogeneous characters inside a narrow area (Eastern Liberia, Côte d'Ivoire and most part of Lower Guinea). In fact, it seems that, a related region, there is a relation between climate and populations. Indeed, when the climate is more or less uniform, populations are homogeneous and conversely when the climate is complex, populations are heterogeneous.
Generally, each character evolves according to a cline which is not the same for all. In this way, Boulenger considered that Sierra Leone forms were specifically different from that of Senegal (see for exemple figure below: sudan form vs Guinean form). Nevertheless, we have shown that along a large geographical gradient each character evolved independently, continuously and gradually. It is the reason why we have proposed the synonymy of B. rutilus with B. macrolepidotus (Paugy, 1982b). See below data of four meristic characters from various part of Africa.
Brycinus macerolepidotus: guinean form (top) vs sudan form (down).
Brycinus macerolepidotus: number of anal fin rays.
Brycinus macrolepidotus: number of lateral line scales (*: plus 1 or 2 scales).
Brycinus macrolepidotus: number of vertebrae.
Brycinus macrolepidotus: number of outer maxillary teeth.
Distribution
Except in Eastern Africa, and particularly in the Zambezi basin, B. macrolepidotus occurs almost throughout intertropical Africa. However, the absence of this species from the Gambia basin is curiously noteworthy (see also Faunafri).
This species has a wide distribution, with no known major widespread threats. It is therefore listed as Least Concern. It has also been assessed regionally as Least Concern for central, eastern, northern and western Africa. The species was only found in the Egyptian upper Nile within the northern Africa region and is now extinct in Egypt.
Major threats: heavy fishing pressure, including from commercial fisheries, may threaten populations of this species.
Bibliography
Brycinus minutus (Hopson & Hopson, 1982)
Type and type locality
Alestes minutus Hopson & Hopson, 1982: 302-304. Type locality: “Lake Turkana at Ilaret, Longech Spit and Kerio Bay”, holotype BMNH n° 1981.2.17.1284, paratypes BMNH n° 1978.5.16.38-42, 1978.5.16.43-48, 1978.5.16.49-58, 1978.5.16.59-64.
Synonyms
Alestes minutus Hopson & Hopson, 1982
Brycinus minutus Seegers et al., 2003
Common names
English: Dwarf Lake Turkana robber (Kenya)
Estonian: Kääbus-kardsalmler
Description
Diagnosis: based on the holotype and on 27 paratypes of 21-33 mm SL. Body compressed, its length 3.3-3.8 times the maximum depth and 3.2-3.7 times the length of the head. Eye 2.3-2.8 times in the length of the head, 0.5-0.8 times in the interorbital width and 0.5-0.6 times in the length of the snout. Mouth superior, slightly subterminal. Caudal peduncle 1.0-1.2 times as long as deep. Pectoral fin 0.5-0.7 times the length of the head. Dorsal fin 0.6-0.8 times the length of the head with II 8 (f=27) rarely II 7 (f=1) rays. Anal fin rays III 13 (f=25) rarely III 12 (f=2) or III 14 (f=1). Scales exceptionally delicate and easily detached, a high proportion missing from all specimens examined. Approximately 31 scales in the lateral line and 5 between the lateral line and the origin of the dorsal fin. Gill rakers 17-19 (M=18). Number of vertebrae 36-38 (M=37).
Premaxilla with 8, more rarely 6 or 7 small teeth in the outer row, usually unicuspid and conical. Occasional tricuspid teeth with two short lateral pointed cusps arising near the apex of the main cusp also noted from time to time in a series of otherwise conical teeth. Eight 5- or 6-cusped inner premaxillary teeth, each broad and somewhat compressed, with the acutely pointed cusps graduated in size forming a regular crest with the largest in the centre. Lower jaw with 8, more rarely 6 or 7 outer 4- or 5-cusped teeth which decrease markedly in size posteriorly. The anterior teeth of the row larger and stouter than the pluricuspid premaxillary teeth, with the principal cusps acutely pointed and backward-curving. Inner row or lower jaw represented by two conical teeth placed anteriorly close together on either side of the mid-line.
Measurements obtained from 22 types are summarized below.
Brycinus minutus: main morphological characters of types.
Maximum reported size: 37 mm FL.
Colour: pale fawn with silvery sales. Fins clear. In formalin-fixed specimens pigmentation very light, confined chiefly to a cluster of melanophores on the dorsal surface of the head and a faint mid-dorsal line along the body. In well-marked specimens an ill-defined black lateral spot on the caudal peduncle and a faint mid-lateral band on the body are also present.
Affinities: distinguished from Brycinus nurse by the shorter snout, slightly larger eye and narrower interorbital space (see figure below). The mouth in this species is noticeably superior and subterminal (cf terminal in B. nurse) and the predominance of unicuspid outer maxillary teeth is in marked contrast to B. nurse where the corresponding teeth are invariably tricuspid. B. minutus also lacks the relatively heavy pigmentation of B. nurse. Compared with B. ferox, the present species is a much smaller fish, and adults of 2-3 cm FL are easily separated from juvenile B. ferox of similar size by the shorter snout lacking the black pigmented spot, fang-like teeth and muzzle-like shape characteristic of the larger species.
Semi diagrammatric representations of the anterior portions of the heads of two Brycinus from Lake Turkana (lateral view).
Reproduction
The species spawns within the lake. Matures at an exceptionally small size for a Brycinus and breeds at a length of 2.5-3.0 cm FL.
Diet
Chiefly zooplankton with occasional small insects.
Commercial importance
Open water surveys indicate that in terms of biomass, B. minutus is by far the most important species of fish in the lake. Due to its small size B.minutus is, however, unlikely to be commercially important unless an industrial fishery is developed in Lake Turkana.
Distribution
A pelagic species, usually occurring together with B. ferox, widespread throughout the open waters of the lake. Situated in the midwater scattering layer during the hours of daylight. Disperses throughout the surface waters after dark. Endemic to Lake Turkana (see also Faunafri).
No noticeable threats or decline.
Major threats: not known.
Bibliography
Brycinus nigricauda (Thys van den Audenaerde, 1974)
Type and type locality
Alestes nigricauda Thys van den Audenaerde, 1974: 143-147. Type locality: “Nipoué ou Cess à Toyébli (6°38’N-8°29’W)”, holotype MRAC n° 73.010.P.1510, paratypes MRAC n° 73.010.P.1511-1516.
Synonyms
Alestes nigricauda Thys van den Audenaerde, 1974
Brycinus nigricauda Paugy, 1990
Common names
Estonian: Mustsaba-kardsalmler
Description
Diagnosis: B. nigricauda is a medium-sized species with a rudimentary adipose eyelid and a pore-like fronto-parietal fontanel in very young individuals disappearing with growth in adults. Body with a humeral spot and a black precaudal blotch, the latter extending partly unto the median caudal-fin rays. Gill rakers are short and thin. Dorsal fin origin at about the same level as pelvic-fin insertions. Jaws equal; premaxilla with two tooth rows, each with 8 teeth; in larger individuals, two teeth of the anterior row become dislodged, thus forming a second row. Scale formula: 4½/22-27/3½. Anal fin with three spines and 11-13 branched rays. Lower (ceratobranchial) limb of first gill arch with 19 or 20 gill rakers. This species shows a sexual dimorphism affecting the anal-fin shape in adult males.
Measurements and counts of the original description, and those of types revised are listed below.
Brycinus nigricauda: main morphological characters of types (* computed from % data; ** longitudinal line scales).
Maximum reported size: 135 mm SL or 177 mm TL.
Colour: body silvery, back more greyish and belly lighter. Fins greyish or colourless, only caudal-fin lobes edged with black.
Affinities: B. nigricauda is close to B. imberi. In the Cess River basin, Thys van den Audenaerde (1974) thought that B. nigricauda replaced B. imberi, but now we know that the two species co-inhabit. B. nigricauda is different from B. imberi in the colouration (caudal-fin edged with a large black band) and because the number of anal fin branched rays and lateral line scales is higher (see table below).
Meristic characters in B. nigricauda and B. imberi from the Cess (Nipoué) River.
Reproduction
All females caught in December were not mature. In April, only one female was in maturation (stage 3). These results are fragmentary, nevertheless we can suppose that this species spawn during the flood, between July and September. Conversely at the same time, 80% of B. imberi females were mature.
Distribution
B. nigricauda is endemic to Cess (Nipoué) River basin (Côte d'Ivoire and Liberia) Turkana (see also Faunafri).
This species is restricted to one river, the Nipoué (or Cess). There are no known major threats to the species. Due to its very restricted range, we can qualify the species as Near Threatened as any identified threat will trigger listing as a threatened species under Criteria B and/or D.
Major threats: no current threats known.
Bibliography
Types and type localities
Myletes nurse Rüppell, 1832: 12. Type locality: “Le Caire”, holotype SMF n° 1051.
Myletes guile Joannis, 1835: 35-38. Type locality: “Nile River at Thèbes”, syntypes MNHN n° A.9717, A.9767 and A.9768.
Chalceus guile Valenciennes, 1849: 255-257. Type locality: “Sénégal”, syntypes MNHN n° A.9717 and A.9768.
Brachyalestes ruppellii Günther, 1864: 315. Type locality: “Chartoum”, syntypes BMNH n° 1862.6.17:15-16.
Alestes erythropterus Pellegrin, 1907: 139. Type locality: “Soubré dans le Sassandra (Côte d'Ivoire)”, syntypes MNHN n° 1907-0320-0321.
Alestes nurse var. nana Pellegrin, 1935. Type locality: “Nanaropus (lac Rodolphe)”, syntypes MNHN n° 1933-0084-0086.
Alestes dageti Blache & Miton, 1960: 100. Type locality: “Lac Tchad à Bangarom”, syntypes MNHN n° 1959-0224, paratypes CEP (Fort Lamy) n° 1082-1089.
Alestes bouboni Roman, 1973: 51-54. Type locality: “Niger à Boubon”, holotype Musée de Haute Volta de Ouagadougou n° 436, allotype Musée de Haute Volta n° 437, paratypes Musée de Haute Volta n° 438-441.
Synonyms
Myletes nurse Rüppell, 1832
Myletes guile Joannis, 1835
Alestes nurse Müller & Troschel, 1845
Chalceus guile Valenciennes, 1849
Brachyalestes nurse Günther, 1864
Brachyalestes ruppellii Günther, 1864
Alestes ruppellii Günther, 1864
Alestes erythropterus Pellegrin, 1907
Brycinus nurse Myers, 1929
Alestes nurse var. nana Pellegrin, 1935
Brycinus nurse nanus Tortonese, 1943
Alestes dageti Blache & Miton, 1960
Brycinus dageti Géry, 1968
Alestes bouboni Roman, 1973
Brycinus bouboni Géry & Mahnert, 1977
Common names
Arabic: Kawara safsaf, Kawwara himila (Sudan)
Dinka, Northeastern: Gudo
English: Characin,Silversides (Ghana), Nurse tetra (Kenya, USA, Global)
Estonian: Sõsar-kardsalmler
Ewe: Atewoe/Dzogbla/Tewoe (Ghana)
Finnish: Isomessinkitetra/Messinkialesti (Finland)
Fulfulde, Pulaar: Debbere (Senegal)
Ga: Tewe kpiti (Ghana)
Hausa: Jam/Kawara/Kudundu/Rajia/Wutsiya (Nigeria)
Ijo: Benibu lou-ipo (Nigeria)
Jula: Kuwulen (Burkina Faso)
Kanuri: Kaya (Nigeria)
Kim: Haï, Han (Chad)
Mòoré: Tatare (Burkina Faso)
Nubian: Girfiga (Sudan)
Nupe: Egbagi (Nigeria)
Shilluk: Agamikak (Sudan)
Soninké: Gicce (Senegal)
Yoruba: Ajarapo (Nigeria)
Zande: Munya (Sudan)
Description
Diagnosis: B. nurse is a medium-sized species with a rudimentary adipose eyelid and a pore-like fronto-parietal fontanel in very young individuals disappearing with growth in adults. In the two dwarf lacustrine populations (B. nurse var. nana from Lake Turkana and B. nurse var. dageti from Lake Chad) the fronto-parietal fontanel is still opened. At the same length, young specimens of B. nurse have also a pore-like opened fontanel but they are never mature. According to Monod (1950), the fronto-parietal fontanel is a primitive character which would be specific in Alestes but only a juvenile character in Brycinus. In B. nurse gill rakers are numerous, long and thin. This species exhibits sexual dimorphism of the anal fin shape in adult males. This phenomenon exists also in dwarf populations. Jaws equal; premaxillary with 2 tooth rows, each comprising 8 teeth; in larger individuals, 2 teeth of the anterior row become dislodged, thus forming a “third” row. Body with a humeral spot as well as a black precaudal blotch, the latter extending unto the median rays of caudal fin to margin of caudal fork. Dorsal-fin origin at about the same level as pelvic-fin insertions. Scale formula: 5½/24-34/3½. Anal fin rays III-10-15. Gill rakers on lower limb of first arch 14-20.
Measurements and counts of the different types described are listed below
Brycinus nurse: main morphological characters of types and additional material.
Maximum reported size: 213 mm SL.
Colour: back greenish, sides silvery and belly white. Unpaired fins vermilion; pectoral and pelvic fins colourless or, at most, light orange. Upper part of eye red.
Affinities: B. nurse is close to B. affinis and B. jacksonii, but these three species have not the same geographical distribution. In B. affinis, the dorsal fin is entirely behind the base of the ventral fins while at the same level in B. nurse. The distinction with B. jacksonii is more difficult. In B. jacksonii, snout is shorter (3.8-4.1 times in length of the head vs 2.8-3.6 in B. nurse). For more details see the description of B. jacksonii.
Growth
Length growth of B. nurse was carried out in Niger (Daget, 1952) and Bandama (Paugy, 1979-80b) Rivers. In the Niger basin, as for others Alestes s.l., growth marks a six months stop which corresponds with the low diet possibilities. As a general rule, growth seems faster in Côte d'Ivoire and at respectively 1 and 2 years B. nurse measures 108 and 158 mm SL vs 92 and 125 mm SL in the Niger River.
Brycinus nurse: growth in length in two West African rivers.
See below growth parameters computed for each river population:
Reproduction
In Côte d'Ivoire sexual maturity is reached at the end of the first year and the spawning period lasts between July and September during the flood. In the Lake Turkana breeding takes place in March during the maximum of the rainy season. As for all Alestes s.l. fecundity of B. nurse is high. For females from Côte d'Ivoire, we give below the different relations that exist between fecundity (F) and standard length (SL), body weight (W) and gonads weight (GW):
Brycinus nurse: fecundity (F) in relation with length (SL), body weight (W) and gonad weight (GW). Data recorded in Côte d’Ivoire.
So the relative fecundity is comprised between 339,000 (Albaret, 1982) and 368,000 (Paugy, 1979-80b) per kg. Among Alestes s.l. species from Côte d'Ivoire, B. nurse is that which has the highest fecundity. These results seem also higher than those observed in the Niger River, where only 17,000 eggs were counted in a 164 mm SL female.
In the Asa Reservoir (Nigeria), the fish spawns during the rainy season from March to August, with peak spawning in March, June and July, months coinciding with the onset of the rains and flooding. The Gonadosomatic Index (G.S.I) ranged between 0.02-29.25% with a mean of 6.43 varying with season, size of fish, sex and stage of gonadal maturity. The absolute fecundity ranged between 1,720 - 68,700 eggs with a mean of 18,281 eggs while relative fecundity ranged from 19,933 to 849,453 eggs/kg with a mean of 345,000 eggs/kg of body weight. Egg diameter ranged from 0.49 to 0.82 mm with a mean of 0.63 mm. It seems that the River Asa population of B.nurse had lower mean values of G.S.I, egg diameter, and relative fecundity but higher estimates of absolute fecundity than other populations, previously studied. These differences were thought to have emanated from differences in geographical location (Saliu & Fagade, 2003).
Diet
B. nurse has a very various diet which seems adapted to the more abundant species (see table below). An additional proof is given in a detailed study carried out in the Lake Chad (Robinson & Robinson, 1969). In the littoral zone where the available food is larger, they eat on zooplankton and insects whereas in the pelagic zone where the food is less diversified, the stomach content is only constituted by zooplankton. In the same way, there is a difference between the stomach contents according to the period of the day. These differences are in relation with the preys abundance during the nychthemeral cycle.
B. nurse : diet in different regions of Africa.
Populations
Considering the entire distribution of the species, it may be possible to distinguish two major groups on the basis of some meristic characters. The first includes the Nilo-Sudan forms which are more slender (SL/body depth > 3.3) et have more lateral line scales (mean > 30). The second includes thick forms from western coastal basin (plus Gambia and Corubal) (SL/body depth < 3.3) which have less lateral line scales (mean < 30). Between specimens from the Senegal River basin are thick but have numerous scales (see tables and figure below). Coincidence between the two lakes Turkana and Chad is too evident to be only fortuitous and it can be estimated that these dwarf forms are lake’s subspecies. So, we can distinguish three subspecies:
Finally B. bouboni described from the Niger River basin is a typically B. nurse as in morphological characters as in colouration.
Brycinus nurse: number of anal fin rays.
Brycinus nurse: number of lateral line scales (*: plus 1 or 2 scales).
Brycinus nurse: number of vertebrae.
Brycinus nurse: mean standard length (SL) / body depth ratio.
Brycinus nurse: variations in the mean number of lateral line scales and the mean standard lenth / body depth ratio in different African river basins.
Distribution
B. nurse is widely distributed in all the great Nilo-Sudan basins: Nile (downstream of Murchison Falls), Omo (including the Lake Turkana), Chad, Niger (including the Benue river), Volta, Senegal and Gambia. It is also found in Western Africa (Corubal and Konkouré) in coastal basins of Côte d'Ivoire (Sassandra, Bandama, Agnébi, Comoé and Bia), from Togo to West Cameroon (Mono, Sio, Ouémé, Ogun, Cross and Mémé). But it is absent in the Guinean dorsal rivers (from Great Scarcies to Cavally) (see also Faunafri).
This species has a wide distribution, with no known major widespread threats. It is therefore listed as Least Concern. It has also been assessed regionally as Least Concern for eastern Africa. Due to uncertainty of this species distribution, it has been assessed as Data Deficient for northern and north eastern Africa. In the central Africa regional assessment it has been categorised as Not Applicable as it is thought that less than 5% of this species range falls within this region.
Major threats: populations of this species are threatened by heavy commercial fishing pressure for the aquarium trade. In northern Africa, dams, water pollution (agriculture, domestic and commercial/industrial), groundwater extraction and drought all pose possible threats.
Bibliography
Brycinus opisthotaenia (Boulenger, 1903)
Type and type locality
Alestes opisthotaenia Boulenger, 1903: 22. Type locality: “Kribi River”, syntypes BMNH n° 1902.11.12:109; 1903.7.28:128-129;1903.7.28:131.
Synonyms
Alestes opisthotaenia Boulenger, 1903
Aletobrycon taeniurus opisthotaenia Hoedeman, 1951
Brycinus opisthotaenia Géry, 1968
Common names
Estonian: Sabaküüt-kardsalmler
Description
Diagnosis: medium-sized species without adipose eyelid. Fronto-parietal fontanel in very small individuals, disappearing with growth, when specimens reach 70-80 mm SL. Gill rakers short but numerous, 16-25 on lower limb of first arch. Dorsal fin origin slightly behind level of pelvic fin insertion. 8 outer premaxillary teeth aligned in a single row.
Measurements and counts of the original description, those of the syntypes revised and of 29 specimens from Cameroon are listed below:
Brycinus opisthotaenia: main morphological characters of types and additional material (* total length).
Maximum reported size: 127 mm SL.
Colour: back brown, flanks silvery and belly white. Body with a black humeral spot [in the Niari river, it would seem that humeral spot is missing (Daget, 1961b)], and a dark longitudinal band extending onto the median rays of caudal fin to the margin of the caudal fork, wider and somewhat indistinct anteriorly, thiner and well pronounced posteriorly.
Affinities: this imberi-group species can be easily identified by its coloration and its distribution. B. opisthotaenia is close to B. carolinae but has a less wide head (head length/head width: 2.0-2.2 vs 1.6-1.9) and less deep body (standard length/body depth: 3.1-4.2 vs 2.8-3.0). Outer premaxillary teeth aligned in a single row instead two for B. carolinae. For a long time, there was confusion between B. kingsleyae and B. opisthotaenia. But a morphological study of these two species showed that some characters and the color pattern clearly separate these putative species (Kamdem Toham & Teugels, 1997). B. kingsleyae consistently displayed a lateral black band that does not reach the vertical of the posterior base of the dorsal fin. Conversely, B. opisthotaenia showed a lateral black band that extend from at least the vertical of the posterior dorsal fin to the middle caudal fin rays (see fifure below).
Color patterns in B. kingsleyae (left) and B. opisthotaenia (right) based on 10 specimens. The blue vertical line marks the vertical of the posterior dorsal fin and allows distinguishing the two species.
The existence of two species based on their difference in colour pattern is confirmed by some morphometric data. Thus, the diameter of the eye is significantly smaller in B. kingsleyae and the pelvic and pectoral fins, are significantly longer in B. opisthotaenia. The existence of two species is further supported by meristic counts, especially the number of anal branched rays. Altough, an interbasin variation was observed for this character, the median values of both species are significantly different (Kamdem Toham & Teugels, 1997).
Distribution
B. opisthotaenia was described from the Kribi basin and Mvile river (Lokoundjé basin), South Cameroon . Found also in the Sanaga and Ntem basins in Cameroon, Mbini (Woleu, Benito) and Ogowe basins in Gabon and Kouilou basin in Congo and Dja system (Congo basin). Not reported from the Nyong and Nyanga basins (see also Faunafri).
The species is widespread or without major threats throughout Central Africa and is assessed as Least Concern.
Major threats: none known.
Bibliography
Brycinus peringueyi (Boulenger, 1923)
Type and type locality
Alestes peringueyi Boulenger, 1923: 437. Type locality: “Mansa River (N. Rhodesia)”, holotype SAM n° 14530.
Synonyms
Alestes peringueyi Boulenger, 1923
Brycinus peringueyi Poll, 1976
Common names
Estonian: Mweru kardsalmler
Description
Diagnosis: medium-sized species without adipose eyelid. Fronto-parietal fontanel in very small individuals, disappearing with growth, when specimens reach about 60 mm SL. Gill rakers short but numerous, 17-22 on lower limb of first arch. Supra-orbitary bone well developed. 8 outer premaxillary teeth aligned in a single row.
Measurements and counts of the original description, those of the holotype revised and of 22 specimens from Katanga ( Congo basin) are listed below:
Brycinus peringueyi: main morphological characters types and additional material (* total length).
Maximum reported size: 121 mm SL.
Colour: body with a black humeral spot and a dark longitudinal band extending from the middle of the space ranging between the ventral and the anal fins onto the median rays of caudal fin to the margin of the caudal fork, wider anteriorly and thiner posteriorly.
Affinities: B. peringueyi is close to B. kingsleyae, but has pectoral fins inserted below opercular instead backward in B. kingleyae. Moreover, the number of lateral line scales is higher (29-31 vs 26-28).
Distribution
B. peringueyi is endemic to the Luapula-Mweru system (see also Faunafri).
Although there are threats known in the Luapula-Mweru region (overfishing), the species is listed as Least Concern because it has a relatively broad distribution.
Major threats: overfishing in Luapula and Lake Mweru with drawnets threaten the species.
Bibliography
Brycinus poptae (Pellegrin, 1906)
Type and type locality
Alestes poptae Pellegrin, 1906: 367. Type locality: “Congo”, holotype MNHN n° 1890-19.
Synonyms
Alestes poptae Pellegrin, 1906
Brycinus poptae Hoedeman, 1951
Common names
Estonian: Popta kardsalmler
Description
Diagnosis: fronto-parietal fontanel, even in juveniles, and adipose eyelid never present. Body is thick, head is large (head length/head width < 2). Supraorbital bone well-developed. 8 outer premaxillary teeth aligned in a single row. The type has no adipose dorsal fin, but this is an accident because all the other specimens have one.
Measurements and counts of the original description, those of the holotype revised and of specimens from Congo basin are listed below:
Brycinus poptae: main morphological characters of types and additional material.
Maximum reported size: 162 mm SL.
Colour: according to Matthes (1964a): “back is red-brown, flanks coppered with green reflections, low-sides carmine, belly pale, posteriorly carmine suffused (base of the anal fin). Chin pinkish, cheeks silvered; a large blackish band extending from the posterior border of the eye to the caudal peduncle, which has a large oval black spot. In some specimens exists a slight post-opercular blotch. Scales of the flanks borderd with mauve. Eye red; fins vinous red, adipose bordered with brown, ventral and pectoral fins carmine.”
Affinities: B. poptae is close to B. grandisquamis and Poll (1948) considered these two species as synonyms. However, B. poptae has less predorsal scales (8-9 vs 11-13) and its general aspect is more thick. In the same way, it has less predorsal scales than B. carmesinus (8-9 vs 11½).
Reproduction
According to Matthes (1964a) all the specimens from the Tshuapa river were mature in September. In August, a male was at the beginning of the maturation. So, it seems that the breeding period takes place during the autumn. According this author, each female lays several thousands of eggs (about 1 mm diameter).
Diet
According to Matthes (1964a) stomach contents are constituted by vegetal and terrestrial insects remains. Therefore, it seems that the species prefers to feed on exogenous items, as it seems the general rule for the macrolepidotus -group species.
Habitat
According to Matthes (1964a) this species is more frequent in medium or little rivers and forms schools of a few tens specimens.
Distribution
B. poptae is found in the central Congo basin up to the tributaries of the Sangha and Ubangi systems(see also Faunafri).
The species is widespread or without major threats throughout the Central Africa assessment region and is assessed as Least Concern.
Major threats: none known.
Bibliography
Brycinus rhodopleura (Boulenger, 1906)
Type and type locality
Alestes rhodopleura Boulenger, 1906: 547. Type locality: “lac Tanganika, delta de la Malagarazi (Congo)”, syntype MRAC n° 89620-89621.
Synonyms
Alestes rhodopleura Boulenger, 1906
Alestes macrolepidotus (non Valenciennes) Boulenger, 1898
Alestes macrolepidotus (partim) Boulenger, 1901
Brycinus rhodopleura Myers, 1929
Alestes macrolepidotus rhodopleura Hoedeman, 1951
Common names
Estonian: Tanganjika kardsalmler
Swahili: Kologo, Kolokolo (Tanzania)
Description
Diagnosis: large sized species without adipose eyelid and fronto-parietal fontanel, even in juveniles. Humeral spot is absent but it exists a large precaudal blotch extending onto the median rays of caudal fin to the margin of the caudal fork. Gill-rakers are short and few numerous. Dorsal fin is inserted very behind vertical base of the ventral fins. 10 outer premaxillary teetn aligned in a single row.
Measurements and countings of the original description, those of one syntype revised and of six specimens from the Lake Tanganyika are listed below:
Brycinus rhodopleura: main morphological characters of types and additional material (* total length).
Maximum reported size: 300 mm SL.
Colour: according to the Boulenger's description (Boulenger, 1906b): “olive green above, silvery below, with an ill-defined pink band along each side, beginning on the gill-cover; a large blackish (in life dark green) patch on caudal peduncle and root of caudal”.
Affinities: because of its distribution, B. rhodopleura may not be confused with others Brycinus. This species is close to B. macrolepidotus but has less scales below the lateral line (2½ vs 3½), more predorsal scales (12½-13 vs 9½-12) and the outer premawillary teeth aligned in a single row. In B. macrolepidotus two of which shift progressively backwards with growth. According to Poll (1950) B. rhodopleura would originate from the Congolese species B. grandisquamis. We think that it is a lacustrine species close to B. macrolepidotus. Its adaptation to lacustrine conditions appears total and spawning period takes place in the lake itself. Conversely the others alestids species go up in the tributaries of the lake to reproduce.
Remarks: four species, with limited distribution) are very close to B. macrolepidotus: B. batesii (Cameroon), B. brevis (some coastal rivers in Ghana and Nigeria), B. rhoddopleura (Lake Tanganyika) and B. schoutedeni (South Cameroon to Congo). A study in progress indicates that these species have characters which exhibit a clinal geographic variation. Similar, clinal variation was already observed in West Africa (Paugy, 1982 b). In anticipation of the conclusions of the ongoing study, B. macrolepidotus is generally considered the only species of this group present in Africa.
Reproduction
According to Poll (1953), B. rhodopleura spawn during the rainy season during a rather long period.
Diet
B. rhodopleura is omnivorous and eats plants, terrestrial insects and small fishes (Worthington & Ricardo, 1937; Hulot, 1950). Its diet is the same as observed in all the macrolepidotus -group species.
Distribution
B. rhodopleura is endemic in Lake Tanganyika (see also Faunafri).
Wide distribution and no major widespread threats identified.
Major threats: fisheries pressure. Pollution in the littoral zones and rivers deltas.
Bibliography
Brycinus sadleri (Boulenger, 1906)
Types and type localities
Alestes sadleri Boulenger, 1906: 435. Type locality: “Entebbe”, syntypes BMNH n° 1909.5.30:105-106.
Micralestes lerneri Nichols & La Monte, 1938: 1-2. Type locality: “Lake Victoria”, holotype AMNH n° 13736, paratypes AMNH n° 13737.
Synonyms
Alestes sadleri Boulenger, 1906
Micralestes lerneri Nichols & La Monte, 1938
Alestes (Alestiops) sadleri Hoedeman, 1951
Micralestes (Micralestes) lerneri Hoedeman, 1959
Brycinus lerneri Géry, 1968
Brycinus sadleri Seegers 1996
Common names
English: Sadler's robber (Kenya, Rwanda, Tanzania)
Estonian: Sadleri kardsalmler
Luo: Soga (Kenya)
Luyia: Nsoga (Kenya)
Not specified: Nsoga (Uganda)
Rwanda: Ikiraba/Inshoga (Rwanda)
Swahili: Osoga (Kenya, Tanzania), Soga (Tanzania)
Description
Diagnosis: a small-sized species not exceeding 100 mm SL. Fronto-parietal fontanel present, even in adults, adipose eyelid absent. Gill-rakers are rather numerous and long. 8-10 outer premaxillary teeth aligned in one or two rows. Sexual dimorphism of anal fin shape in adult males.
Measurements and counts of the original description, those of one syntype revised and of specimens from the lakes Ihema and Victoria are listed below:
Brycinus sadleri: main morphological characters of types and additional material (* total length).
Maximum reported size: 107.8 mm SL, which corresponds to 137.9 mm TL (Seegers, 1996).
Colour: humeral spot is absent but it exists a large precaudal blotch extending onto the median rays of caudal fin to the margin of the caudal fork. A black longitudinal band along the flanks (on scales row 4½-5½) from the gill cover to the caudal fin.
Affinities: B. sadleri is close to B. lateralis but has more predorsal scales (12½-14 vs 11-11½). In B. sadleri origin of the dorsal fin behind that of the ventrals while they are at the same level in B. lateralis. B. sdaleri has more gill-rakers than B. tessmanni (18-22 vs 16-17) and more scales above the lateral line than B. humilis (5½ vs 4½). Finally, B. sadleri has more outer premaxillary teeth than B. leuciscus, B. luteus, B. bartoni, B. longipinnis, B. derhami, B. intermedius and B. tholloni (8-10 vs 6).
Diet
In Lakes Victoria and Kyoga and according to the biotopes B. sadleri eats aquatic plants or aquatic insects (Chironomids and Ephemeroptera). Conversely to B. jacksonii, B. sadleri never eats fish (Corbet, 1961).
Comparison of diets before and after the environmental changes in Lake Victoria showed a shift to more generalist feeding (Wanink & Joordens, 2007) (see figure below). The main food sources in the 1950s were plants during daytime and surface insects at night. Hardly any plant material was eaten during the late 1980s, but chironomid larvae, chaoborid larvae and pupae, shrimps, Odonata nymphs and fish contributed to a broader daytime diet. These prey species were also commonly taken at night, though, like in the 1950s, surface insects accounted for the major part of the diet. It was also found dietary shifts during ontogeny. Juveniles fed exclusively on zooplankton. Chironomid larvae, relatively large food items in comparison with zooplankton, were the key prey of sub-adult fish. Their importance decreased in the diet of adults, which included even larger prey like shrimps, Odonata nymphs and fish. At night, surface insects replaced chironomid larvae in the diet of adult fish (see figure below). Diet expansion may result from reduced competition after the decline in fish mass following the Nile perch boom. An alternative explanation, increasing the prey spectrum in response to deteriorated light conditions, is not likely to hold for B. sadleri. The ontogenetic shift to increasingly larger prey and the nocturnal shift to surface insects probably reflect optimal foraging behaviour and diel vertical migration patterns of the fish respectively. These dietary shifts emphasize the feeding flexibility of B. sadleri, which may have been essential in surviving the environmental changes in Lake Victoria (Wanink & Joordens, 2007).
Dietary shifts in Brycinus sadleri: diet composition (volume percentages) before (recalculated from Corbet, 1961) and after the environmental changes plotted as a function of fish size broken down by sampling year and diurnal phase. Numbers of non-empty stomachs checked indicated above the bars (redrawn from Wanink & Joordens, 2007).
In lake Nabugabo, B. sadleri generally actively foraged during the daylight hours and remained quiet during the night (Olowo et al., 2004).
Brycinus sadleri: feeding activity of in an exposed (exposed to Nile perch predation) site of Lake Nabugabo, Uganda in 1995. The bars represent the percentage of fish examined that had empty or full stomachs (expressed as a percentage of all stomachs examined) (left), the average number of individual prey items per fish (right) Averages for right bars are based on the total number of fish examined for each time interval. Only stomachs rated as completely full or empty were used in the comparison of full and empty stomachs (redrawn from Olowo et al., 2004).
Habitat
In the Lake Victoria, B. sadleri is found along not very deep banks. In the Lakes Kyoga and Nabugabo it stays along banks in aquatic plants. Generally this species likes to form schools of few hundreds specimens.
In Lake Nabugabo (Uganda), B. sadleri are more abundant in exposed habitats (off-shore) than in the wetland habitats, and habitat and distance from shore are significant factors affecting B. sadleri abundance (Olowo et al., 2004). To summarize, we can consider that B. sadleri are more abundant in areas 20m offshore than in inshore areas and more abundant in exposed (exposed to Nile perch predation) habitats than in wetland habitats.
Distribution
B. sadleri is endemic in the lake Victoria basin: lakes Victoria, Kyoga, Nabugabo and Ihema; Victoria Nile and Malawa rivers (see also Faunafri).
Brycinus sadleri has a large extent of occurrence; it is known from the Lake Victoria basin, Lake Rukwa basin and the Malagarazi River. It appears to have persisted with Nile Perch. Apart from local threats in the Lake Victoria and Malagarazi basins, no major widespread threats have been identified. This species is therefore listed as Least Concern.
Major Tthreats: in the Lake Victoria basin possible threats include: eutrophication, water turbidity and siltation as a consequence of erosion and farming extension on the watersheds and floodplains; loss of riverine migratory routes, and fishing. Predation by Nile Perch has been observed in Lake Nabugabo, although remarkable resilience has been reported by Olowo et al. (2004). In the Malagarazi basin sedimentation and increased use of agrochemicals (pesticides and fertilizers) as a result of agricultural expansion, and pollution from future mining activities (nickel, gold) are threats in the upper catchment (West 2001).
Bibliography
Brycinus schoutedeni (Boulenger, 1912)
Type and type locality
Alestes schoutedeni Boulenger, 1912: 7. Type locality: “Lebuzi à Kuka-Muno et Boma Vonde”, syntypes BMNH n° 1912.4.1:241-243. Type locality: “Kuka-Muno”, syntypes MRAC n° 1599-1600.
Synonyms
Alestes schoutedeni Boulenger, 1912
Brycinus schoutedeni Myers, 1929
Alestes macrolepidotus schoutedeni Hoedeman, 1951
Common names
Estonian: Schoutedeni kardsalmler
German: Großschuppen-Brycinus
Description
Diagnosis: B. schoutedeni is a macrolepidotus-group species, which has neither adipose eyelid nor fronto-parietal fontanel. Gill-rakers are thin and rather short. Supraorbital bone is rather few-developed. 8-10 outer premaxillary teeth, two of which shift progressively backwards with growth. This species exhibits no sexual dimorphism of anal fin shape in adult males.
Measurements and counts of the original description, those of syntypes revised and of specimens from Niari and Congo are listed below:
Brycinus schoutedeni: main morphological characters of types and additional material (* total length).
Maximum reported size: 205 mm SL
Colour: body with a humeral spot and a broad black precaudal spot. Sides sometimes with a broad dark longitudinal band running from gill cover to caudal fin. Fins greyish and black-edged.
Affinities: B. schoutedeni is close to B. poptae, B. carmesinus and B. grandisquamis. It is distinguished from the first by higher number of predorsal scales (10½-11½ vs 8-9), by less high body than the second (SL/body depth > 3.4 vs SL/body depth <3.0) and by higher number of scales below lateral line than the third (3½ vs 2½).
Remark: B. schoutedeni is very similar to B. macrolepidotus and the justification for maintaining separate species is questionable. If we consider the Lower Guinean populations and the distribution of different forms (according to collection determinations), it should be noted that a B. macrolepidotus “form” is only found in Northern regions while a B. schoutedeni “form” is found only in Southern regions. However, between these two forms there appears to be a mixing and intermediacy of forms. Actually, we consider that there are several populations which have evolved in a geographical gradient to produce different morphotypes of a single species.
Four species, with limited distribution) are very close to B. macrolepidotus: B. batesii (Cameroon), B. brevis (some coastal rivers in Ghana and Nigeria), B. rhoddopleura (Lake Tanganyika) and B. schoutedeni (South Cameroon to Congo). A study in progress indicates that these species have characters which exhibit a clinal geographic variation. Similar, clinal variation was already observed in West Africa (Paugy, 1982 b). In anticipation of the conclusions of the ongoing study, B. macrolepidotus is generally considered the only species of this group present in Africa.
Distribution
B. schoutedeni is endemic in the Lower Guinean province from South Cameroon to Congo: Cross, Mungo, Wouri, Sanaga, Nyong, Lokoundjé, Kienké (Kribi), Ntem, Campo, Mbini (Woleu, Benito), Como , Ogowe, Nyanga, Kouilou and Loémé basins (see also Faunafri).
IUCN assessment
Not evaluated.
Bibliography
Brycinus taeniurus (Günther, 1867)
Type and type locality
Alestes taeniurus Günther, 1867: 113. Type locality: “Gabon”, holotype BMNH n° 1867.5.3:26.
Synonyms
Alestes taeniurus Günther, 1867
Alestobrycon taeniurus taeniurus Hoedeman, 1951
Brycinus taeniurus Géry, 1968
Common names
Estonian: Juttsaba-kardsalmler
Description
Diagnosis: B. taeniurus has neither fronto-parietal fontanel nor adipose eyelid. Gill rakers are long, thin and rather numerous (24-28 in lower limb of first arch). 8 outer premaxillary teeth aligned in a single row. Dorsal fin origin is slightly behind level of pelvic fin insertion. Scale formula: 4½/25-28/3½. Anal fin rays III-15-17. The species exhibits a sexual dimorphism affecting the anal fin shape in adult males.
Measurements and counts of the original description, those of holotype revised and of specimens from Ogowe are listed below:
Brycinus taeniurus: main morphological characters of types and additional material.
Maximum reported size: 98 mm SL.
Colour: body with a black precaudal blotch extending unto the median rays of caudal fin to margin of caudal fork. Humeral spot not always present. Body with a thin band on the upper third of the scales, originating at vertical through pelvic fin origin and extending to caudal fin base. According to Pellegrin (1907b): “in male, the black longitudinal band which gives its name to the species does not start as in the female at vertical of pelvic-fins origin, but little forward”.
Affinities: B. taeniurus is close to B. opisthotaenia and especially to B. kingsleyae. But generally, it has no humeral spot (which is always present in the two other species) and has more numerous gill rakers on lower limb of first arch (24-28 vs 16-25 in B. opisthotaenia and 16-21 in B. kingsleyae). But the more discriminatory character is the longitudinal band shape which is very thin (restricted to upper third of each scale) in B. taeniurus, while larger (one scale width) in B. opisthotaenia and B. kingsleyae.
Distribution
A Lower Guinea endemic species found mainly in the Ogowe and Ntem basins. Some specimens have also been collected in the Kribi (Kienké) basin (see also Faunafri).
This species is reasonably widespread and there are no major current threats known.
Major threats: there are currently no threats. The locality on the Lower Kouilou River is possibly threatened. The Dimonika Biosphere Reserve has not been managed since 1997 due to civil unrest. A potential threat to the species is gold mining, where this would lead to high levels of sedimentation and canalisation (it is not though that mercury will be used). An additional There is a potential threat is the construction of a dam (Sunda) on the Lower Kouilou, which was started before the war and stopped in 1997. It is likely to start again. It is not known if the reservoir that would be formed would impact the species.
Bibliography
Brycinus tessmanni (Pappenheim, 1911)
Type an type locality
Alestes tessmanni Pappenheim, 1911: 510. Type locality: “South Cameroon”, holotype ZMHU n° 18376.
Synonyms
Alestes tessmanni Pappenheim, 1911
Alestes (Alestiops) tessmanni Hoedeman, 1951
Brycinus tessmanni Géry, 1968
Common names
Estonian: Tessmanni kardsalmler
Description
Diagnosis: fronto-parietal fontanel present, even in adults, adipose eyelid absent. It is a longipinnis -group species.
Measurements and counts of the original description and those of holotype revised (we were not able to examine specimens of this species, but Professor H.J. Paepke of the Berlin Museum was very kind to do for us counts and measures of the holotype) are listed below:
Brycinus tessmanni: main morphological characters of the holotype (* total length).
Maximum reported size: 126 mm SL
Affinities: B. tessmanni is distinguished from longipinnis-group species (B. bartoni, B. longipinnis, B. derhami, B. intermedius and B. tholloni) by a high number of outer premaxillary teeth (8 vs 6). It has a higher number of scales above lateral line than B. humilis (6½ vs 4½) and less gill rakers than B. lateralis (16-17 vs 18-22). Moreover it is allopatric with these two species.
Distribution
Only known by the types from the “Bimfilli fluss”, South Cameroon (see also Faunafri).
IUCN assessment
Not evaluated.
Bibliography
Brycinus tholloni (Pellegrin, 1901)
Type and type locality
Alestes tholloni Pellegrin, 1901: 329. Type locality: “Congo”, syntypes MNHN n° 1890.21-22.
Synonyms
Alestes tholloni Pellegrin, 1901
Alestobrycon tholloni Hoedeman, 1951
Brycinus tholloni Géry, 1968
Common names
Estonian: Tholloni kardsalmler
Description
Diagnosis: fronto-parietal fontanel always present, even in adults, but no adipose eyelid. A black humeral spot and a black precaudal spot extending onto proximal portion of median rays. Gill rakers thin, short and few. The 6 outer premaxillary teeth aligned in a single row.
Measurements and counts of the original description and those of syntypes revised are listed below:
Brycinus tholloni: main morphological characters of the holotype.
Maximum reported size: 89 mm SL.
Colour: ground colour silvery, back greenish, belly whitish and fins greyish. A black humeral spot and a black precaudal spot extending onto proximal portion of median rays of the caudal fin are present.
Affinities: B. tholloni is close to B. bartoni, B. longipinnis, B. derhami and B. intermedius. It is distinguished from the first three species by higher number of scales above the lateral line (6½ vs 5½) and from B. intermedius by a higher number of branched anal rays and lateral line scales (22-25 and 34-38 vs 19-21 and 31-35, respectively).
Distribution
A rather rare Lower Guinea endemic species found in the upper Ogowe, Nyanga (South Gabon) and Kouilou (Congo) basins (see also Faunafri).
This species is reasonably widespread and there are no major current threats known.
Major threats: There are currently no threats. The locality on the Lower Kouilou River is possibly threatened. The Dimonika Biosphere Reserve has not been managed since 1997 due to civil unrest. A potential threat to the species is gold mining, where this would lead to high levels of sedimentation and canalisation (it is not though that mercury will be used). An additional There is a potential threat is the construction of a dam (Sunda) on the Lower Kouilou, which was started before the war and stopped in 1997. It is likely to start again. It is not known if the reservoir that would be formed would impact the species.
Bibliography
