| Family: |
Alestidae (African tetras) |
| Max. size: |
53 cm SL (male/unsexed); max.weight: 2,000.0 g |
| Environment: |
pelagic; freshwater; brackish, potamodromous |
| Distribution: |
Africa: present throughout intertropical Africa (Ref. 2880, 80290, 81279). Absence from the Gambia basin is noteworthy (Ref. 81279). Present in the Nile system (Ref. 28714, 58460) up to Lake Albert (Ref. 4903) and in Lake Turkana system (Ref. 28663). Widely distributed in the Congo River basin (Ref. 5331, 42019, 42510, 45434). |
| Diagnosis: |
Anal spines: 0-0; Anal soft rays: 13-19. Diagnosis: fronto-parietal fontanel absent in adults, sometimes pore-like in juveniles; snout long, comprimised 3x in head length; dorsal fin origin distinctly behind pelvic fin insertion; adults large-sized; no sexual dimorphism affecting anal fin shape; 21-31 lateral line scales; 4.5 scales between lateral line and dorsal fin; 10-16 anal fin branched rays; 14-22 gill rakers on lower limb of first gill arch; 8-14 teeth in outer premaxillary row (Ref. 2880, 80290, 81279). Head length/snout length 2.6-2.9; 10-12 predorsal scales (Ref. 80290). Body depth more than 3x SL in adults (Ref. 2880, 81279).
Description: anal fin with 3 branched and 10-16 unbranched rays; 8-14 premaxillary teeth, two of which shift progressively backwards with growth; supraorbital bone well-developed; upper jaw projecting beyond lower jaw in adults (Ref. 2880, 80290, 81279).
Coloration: humeral spot; black precaudal blotch extending partly unto median caudal-fin rays; greenish back, white belly; juveniles with white spot on upper part of caudal peduncle (Ref. 2880, 80290, 81279). Sides sometimes with an orange (Ref. 2880, 81279) or broad dark (Ref. 80290) longitudinal band from opercle to caudal fin in adults only. This color pattern is not correlated with sexual activity (Ref. 2880, 80290, 81279). In most fish fin color varies from red-orange or pink (Ref. 2880, 80290, 81279) to grey (Ref. 80290). In some populations fin margins are trimmed with dark pigment (Ref. 80920). Only live specimens from Cavally River (Côte d'Ivoire) have vermillion red fins (Ref. 2880, 81279). |
| Biology: |
More common in rivers than lakes; feeds on insects, crustaceans, fish, vegetation and debris (Ref. 28714). Considering the distribution of different forms (according to collection determinations), it should be noted that a B. macrolepidotus 'form' is found only in northern regions, while a B. schoutedi 'form' is found only in southern regions. However, between these two forms there appears to be mixing and intermediacy of forms. We consider that there are several populations which have evolved in a geographical gradient to produce different morphotypes of a single species (Ref. 80290). |
| IUCN Red List Status: |
Least Concern (LC); Date assessed: 16 April 2019 Ref. (130435)
|
| Threat to humans: |
harmless |
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