Nile tilapia - Oreochromis niloticus
(Linnaeus, 1758) [Cichlidae]
FAO official common names: Fr - Tilapia du Nil; Es - Tilapia del Nilo
Taxonomic and biological features:
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Distinguishing characters
Body shape generally laterally compressed to oval and deep, though variable depending on the environment (Figure 1). D XVI-XVIII, 12-14, A III, 9-11. Lateral line interrupted with 30-34 cycloid scales. Mouth terminal. Gill rakers on lower limb of first gill arch 20-26. Vertebrae 30-32. Caudal fin has 7-12 distinct vertical stripes. Breeding males with red flush to head, lower body, dorsal and caudal fins. Caudal fin truncate (Figures 2 and 3). Genital papillae of male short and conical or bluntly bifid at tip and not tessellated. Teeth in the jaws in 3 to 7 series, the number of which is size dependent. The outermost teeth are bicuspid and in adults with stout shafts and obliquely truncate major cusps. Lower pharyngeal with firm teeth in approximately triangular dentigerous area. The most diagnostic features are the regular and definitive stripes on the caudal fin, the red flush of the breeding male and the dark margin of the dorsal fin. Body colouration varies depending on environmental, physiological and dietary factors.