| Diagnosis: |
Dorsal spines (total): 15-16; Dorsal soft rays (total): 10-12; Anal spines: 3-3; Anal soft rays: 8-10. Diagnosis: Coptodon ejagham differs from Tilapia species, except Coelotilapia joka and Congolapia bilineata, and all members of the genus Coptodon in tricuspid, rarely quadricuspid, pharyngeal teeth in the posterior two rows of lower pharyngeal jaw (Ref. 85854). It differs from Coelotilapia joka in more gill rakers on first ceratobranchial, 9-10 vs. 6-8; from Congolapia bilineata in not having a densely scaled caudal fin; it differs from Coptodon walteri, C. rendalli, C. congica and C. dageti in lower body depth, 33.8-40.6% of standard length vs. 41.4-51.3%; from C. cameronensis in lesser number of dorsal rays, 10-12 vs. 13-14; from C. kottae in narrower interorbital width, 9.2-12.2% of standard length vs. 12.4-14.0%; from C. imbriferna in shorter head length, 32.6-39.7% of standard length vs. 40.1-42.6%; from C. thysi in higher number of gill rakers on first ceratobranchial, 9-10 vs. 7-8; from C. snyderae in longer snout length, 13.5-16.9% of standard length vs. 11.3-13.3%; from C. bakossiorum in higher cheek depth, 12.0-15.4% of standard length vs. 8.7-11.2%; from C. bythobates in shorter caudal peduncle length, 12.6-15.7% of standard length vs. 15.9-17.5%; from C. guineensis, C. margaritacea, C. discolor, C. tholloni, C. flava, and C. gutturosa in a lower caudal peduncle depth, 13.0-15.1% of standard length vs. 15.2-19.2%; from C. ismailiaensis, C. camerunensis, C. coffea, C. louka, and C. nyongana in greater lower jaw length, 12.4-16.2% of standard length vs. 7.8-12.2%; and from C. bemini in robust, non-spatulate outer row jaw teeth, vs. gracile spatulate teeth (Ref. 85854). It differs from C. deckerti in shorter eye length, 6.2-8.4% of standard length vs. 8.5-10.7%; from C. nigrans in flank scales with dark scale margins and a light centre, especially on scales below the lateral line, vs. dark square-shaped blotches at base of each flank scale, filled or with a light coloured window at centre of blotch; and from C. fusiforme in greater snout length, 13.5-16.9% of standard length vs. 10.3-13.3% (Ref. 85854). Coptodon spongotroktis is distinguishable by combination of characters: interorbital width, lower jaw length and caudal peduncle length; C. zillii is distinguished by a combination of characters: anal spine length, length of last dorsal spine, snout length, lower jaw length, caudal peduncle depth and head length (Ref. 85854).
Description: A large tilapia species with a laterally compressed body; dorsal head profile moderately concave from insertion of first dorsal spine to upper margin of eye henceforward the head profile changes to slightly convex (Ref. 85854). Large and compact head; snout outline obtuse; eye small and interorbital width always larger than eye length (Ref. 85854). Greatest body depth at level of first dorsal spine; dorsal line slightly posteroventrally curved; caudal peduncle as long as deep (Ref. 85854). Body scales cycloid, chest scales smaller than flank scales and slightly embedded; upper lateral line extending from posterior margin of gill cover to approximately last dorsal ray; upper lateral line separated from first dorsal spine by two to three scale rows; lower lateral line originating at level of first dorsal branched rays and terminates midlaterally on caudal peduncle; one or two scales of lower lateral line extending onto caudal fin; two scale rows between upper and lower lateral line; preoperculum with three to four regular rows; lower one third of pectoral base mostly lacking scales (Ref. 85854). First ceratobranchial with 9-10 gill rakers and first upper gill-arch with 4-5 gill rakers; ceratobranchial rakers stout, broader on base, pointed; gill raker in angle of arch and first four epibranchial rakers more slender, decreasing in size towards last (Ref. 85854). Origin of dorsal fin at level of origin of pelvic fin; first dorsal spine always shortest, last dorsal spine always longest; longest spines always shorter than longest ray; last dorsal ray most deeply branched; caudal fin outline truncate; third anal spine always longest; tip of longest anal fin ray in most cases overlapping hypuralia; last dorsal ray most deeply branched; tip of longest pelvic-fin ray mostly reaching anus (Ref. 85854). Jaws isognathous; upper and lower outer teeth rows in both jaws bicuspid; neck of anterior jaw teeth stout, crown expanded and cusps truncated; two to four incomplete inner rows of smaller tricuspid teeth in both jaws; lower pharyngeal jaw as long as broad, anterior keel shorter than toothed area; posterior pharyngeal teeth tricuspid, rarely quadricuspid, stout, slightly hooked and regularly arranged, especially over the posterior third of the toothed area; dentigerous plate triangular; most of teeth in anterior two thirds of toothed area approach the 'kukri' tooth shape (Ref. 85854).
Colouration: Colouration in alcohol: basic colouration brownish, with head and dorsal side darker than ventral side; flank scales with dark scale margins and light centre, especially on scales below lateral line; lower lip light brownish to whitish and upper lip darker; six to seven dark vertical bars on dorsum and sides, first bar at level of first dorsal spine, last two on caudal peduncle, and a nape band, second vertical bar deeply bifurcated; vertical bars sometimes not present; no longitudinal mid-lateral band; dark and broad lachrymal stripe extending from lachrymal to jaw angle; dark opercular spot; pectoral fins transparent; pelvic fins light brownish, margins transparent; anal fin dark brownish, margins transparent; caudal fin either dark brownish and margins transparent or completely light brownish with light dots in the upper part; dorsal fin dark brownish, margins transparent, 'tilapia' spot mostly not visible, if visible some light dots in soft ray part of dorsal fin are also present (Ref. 85854). Non-breeding colouration in life: basic colouration light greyish, chest and belly pale; upper lip dark and lower lip whitish; a horizontal iridescent blue line above antero-rostral margin of pre-opercle; iris of eyes bright red; body with six to seven black dark vertical bars and a nape band; second bar always deeply bifurcated; dark broad lachrymal stripe extending from lachrymal to jaw angle; dark opercular spot; all fins with yellow colouration at margins except pelvic fins; upper part of caudal fin with yellow dots; in soft part of dorsal fin 'tilapia spot' and a few yellow spots (Ref. 85854). Breeding colouration in life: basic colouration dark brown to blackish, especially on head, chest and belly pale; upper lip dark brownish and lower lip whitish; a horizontal iridescent blue line above antero-rostral margin of preopercle; iris of eyes bright red; no vertical bars; pectoral and pelvic fins transparent; anal fin dark brownish, margins bright yellow; caudal fin dark brownish, margins bright yellow, no dots visible; spiny part of dorsal fin transparent with bright yellow margins and soft part with 'tilapia spot' and a few yellow spots, margins slightly yellow (Ref. 85854). |