Diagnosis |
Diagnosis: Typical tilapiine cichlid, relatively deep bodied, with rather a small head (Ref. 118638). Other distinguishing characters are: caudal fin free of scales except basally; vertebrae 30; scales in lateral line series 30-32; dorsal spines XV-XVII; soft rays usually 11-13; outer teeth bicuspid, in mature fishes occasionally with a few tricuspids; lower gill-rakers 20-22; interorbital region in adults 34.5-40.0% length of head (Ref. 2). Ripe males have a dark body and fins, almost black, with bright red/orange margins on the dorsal and caudal fins; vertical barring can be noticeable in freshly caught specimens; head region in ripe males has a bluish sheen; ripe males have yellow-orange tassels; females and subadult males plain silver/grey with 6-7 post-opercular vertical stripes and bluish snout present in freshly caught specimens (Ref. 118638).
Description: The teeth are in 4-6 series in specimens over 100 mm standard length, 3-4 below this size; with slender shafts and broader, curved crowns; those of outermost row bicuspid except that three mature fishes have a few tricuspids among them; inner rows tricuspid (Ref. 2). Scales on cheek in 2 rows, rarely 2 or 3 scales of a third row present; 4 or 4.5 between origin of dorsal and lateral line (Ref. 2). Caudal fin very slightly emarginate in young, truncate in adults (Ref. 2).
Colouration: Preserved adults are uniformly pale, without markings on the body; the vertical fins and the pelvics are either likewise pale or may be dusky between the rays; the young are also pale, but some show 6-8 grey vertical bands on the flanks and the soft dorsal may be marked with dark oblique bands or with clear ovals on a grey ground; in this pattern the tilapia-mark may be indicated by a darker grey, but most are without even this vestige of a tilapia-mark (Ref. 2). |