Oreochromis mossambicus (Peters, 1852)

Dorsal spines (total): 15 - 18; Dorsal soft rays (total): 10 - 13; Anal spines: 3; Anal soft rays: 7 - 12; Vertebrae: 28 - 31

Diagnosis: snout long; forehead with relatively large scales, starting with 2 scales between the eyes followed by 9 scales up to the dorsal fin . Adult males develop a pointed, duckbill-like snout due to enlarged jaws, often causing the upper profile to become concave , but upper profile convex in smaller specimens . Pharyngeal teeth very fine, the dentigerous area with narrow lobes, the blade in adults longer than dentigerous area; 28-31 vertebrae; 3 anal spines; 14-20 lower gill-rakers; genital papilla of males simple or with a shallow distal notch; caudal fin not densely scaled; female and non-breeding male silvery with 2-5 mid-lateral blotches and some of a more dorsal series; breeding male black with white lower parts of head and red margins to dorsal and caudal fins . Description: moderately deep-bodied , but very variable according to food availability . Head profile straight in juveniles and females . Mouth large . Lower jaw prominent; lips thick . Maxillary ending between nostril and eye in females and immature males , in breeding males mouth reaching to below anterior border of eye or a little beyond . Eye with yellow ring around pupil . Otoliths: sulcus with nearly straight crista inferior at the transition between ostium and cauda (thus no ventralward widening of the ostium is present) . 2-3 series of scales on cheek . Scales cycloid . Scales on belly small, breast scales even smaller . Large scales on opercle , in 3 rows . 17-23 scales in upper part of lateral line, 10-17 in lower part . 9-12 predorsal scales . 15 precaudal vertebrae; 15-16 caudal vertebrae; 12-13 pairs of pleural ribs; 2 pairs of epineurals; 6 pairs of epipleurals; ventral vertebral apothysis on third vertebra . Gill-rakers short and thick . Dorsal fin spines subequal from the sixth; dorsal soft rays a little longer than longest spines . Last dorsal spine the longest . Soft part of dorsal and anal fin long and pointed , especially in males . Dorsal fin with 25-28 pterygiophores . Pectoral fin (nearly) as long as head , pointed , reaching to vent or to a little beyond origin of anal fin . 4-6 scales between bases of pectoral and pelvic fins . Anal fin with 11-12 pterygiophores . Outer rays of pelvic fins slightly produced, reaching to vent or beyond origin of anal . Caudal fin scaly in the basal half , the angles sometimes rounded . Central caudal fin skeleton with 3 epurals, 5 hypurals and 2 pairs of uroneurals . No genital tassel . Coloration: basic melanin pattern of 2 horizontal and 6-7 vertical bars never fully realized; more commonly, at least in preserved specimens, females and sexually inactive males have no bands, but may have the intersection points of the facultative bands represented by 3-4 upper and 2-5 mid-lateral blotches, or some or all of these may be present . Basic body coloration silvery grey to greenish grey, sometimes a more bluish colored head . Belly greyish . Spiny part of dorsal fin light with dark mottling . Soft dorsal and anal, and caudal and pelvic fins blackish . Pectoral fins colorless . Indistinct, dark opercular spot present . Vertical fins uniform , blackish with more or less distinct whitish spots or with large or small, fused or non-fused, dark spots on a pale background , given a darker aspect to these fins . 3 black blotches present in juveniles but