Aphyosemion alpha Huber, 1998
photo by JJPhoto

Family:  Nothobranchiidae (African rivulines)
Max. size:  50 cm TL (male/unsexed); 40 cm TL (female)
Environment:  pelagic; freshwater; pH range: 5.69999980926514; depth range - 0 m, non-migratory
Distribution:  Africa: known from a limited number of localities between Libreville and Cap Esterias in north-western Gabon (Ref. 80395) and Owendo area south of Libreville in Gabon (Ref. 119374).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 12-13; Anal spines: 0-0; Anal soft rays: 13-15; Vertebrae: 24-25. Diagnosis: This is a fairly large species of the subgenus Chromaphyosemion, larger than all its congeners with the exception of Aphyosemion riggenbachi, which has the most forward placed dorsal fin (Ref. 41203). It is a strictly blue phenotype with a unique red marking on the sides of the body with the exception of the gill lids, with two conspicuous, mood-dependent dark longitudinal bands, with a red dotted dorsal fin, a flamed caudal fin and an "undrawn" anal fin, except for a thin red submarginal and white marginal band, with longer trapezoidal vertical unpaired fins and a caudal fin with short extracts in the males; the female also shows the alpha-shaped mark, with striking, dark bandages and an anal fin without spots, but without a dark mesh pattern around the scales on the sides of the body (Ref. 41203). Description: Large, somewhat stout with little lateral compression (Ref. 80395). Short streamers in dorsal end caudal fins; dorsal fin with 12-13 rays; anal fin with 13-15 rays; the ratio D/A = 1-2/1 (Ref. 80395). Scales in longitudinal series 25-26 (+1-2); predorsal scales 12-13; transversal scales 8-9 (Ref. 80395). Colouration: Males light blue on flanks, light brown dorsally and pale orange yellow ventrally; dark red spots, forming horizontal bands dorsally on body and caudal peduncle; just above the pectoral fins two bands of red spots merge to form a larger spot in the shape of the Greek letter 'alpha'; throat usually pale orange; dorsal fin light orange, tinged with pale blue; large dark red spots between dorsal fin rays, with an orange short fin extension; anal fin blue, usually without dark red spots but some may be present basally; anal fin with a narrow dark red band and a light blue margin; caudal fin blue with dark red spots and stripes dorsally; in the lower part of this fin, a dark red band and light blue margin; caudal fin extensions orange (Ref. 80395). Young males with two dark longitudinal bands; when mature these bands are less visible (Ref. 80395). Females yellow-brown with two dark longitudinal bands that remain visible in mature specimens; all fins are colourless except the dorsal which is pale light blue with dark spots (Ref. 80395).
Biology:  This species is found in clear creeks under forest cover, usually over a sandy soil, in the coastal plain (Ref. 80395).
IUCN Red List Status: Endangered (EN); Date assessed: 16 February 2009 (B1ab(iii)) Ref. (130435)
Threat to humans:  harmless
Country info:   
 


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