Tilapia guinasana Trewavas, 1936
Otjikoto tilapia
Tilapia guinasana
photo by Muséum-Aquarium de Nancy/D. Terver

Family:  Cichlidae (Cichlids), subfamily: Pseudocrenilabrinae
Max. size:  14 cm TL (male/unsexed)
Environment:  benthopelagic; freshwater; pH range: 7 - 7.80000019073486; dH range: 15,
Distribution:  Africa: endemic to Lake Guinas, Namibia. Introduced to Lake Otjikoto and several reservoirs in Namibia. Also occurs in subterranean rivers.
Diagnosis:  Description: moderately slender; frontal profile slightly concave; neither sex has noticeably elongated dorsal or anal fin rays (Ref. 52307). Coloration: polychromatic color pattern unique among Tilapia; 6 color morphs currently recognized: dark blue, blue striped, olive, olive striped, pale blue and black; throat, belly and anal fin dusky to blackish in first 2 morphs mentioned; blue morph with blue head, body, dorsal and caudal fin; olive striped morph more bluish-silvery with olive-yellow dots and stripes on body, and with bluish mouth; pale morph with pale throat and some darker shading on belly, its flanks whitish to pale blue, upper parts of head, opercles and back are dusky blue, pelvic, dorsal, anal and caudal fins also pale except anterior part of dorsal fin which is dusky; "tilapia"-spot only visible in small specimens, absent from sub-adult and adult fish (Ref. 52307).
Biology:  Found in deep sinkhole lakes (100 m deep or more, e.g. introduced population in Lake Otjikoto, Namibia) with moderately clear water and with water temperatures ranging from 19 to 27°C (Ref. 6465). Omnivorous (Ref. 52307), but feeds mainly on algae and diatoms (Ref. 6465, 52307). Generally congregate, breed and feed from the near-vertical shores. Use narrow shelves for breeding, with established and defended territories, both parents guard and tend eggs. Threatened due to depletion of local groundwater resources and impact of introduced species (Ref. 7248). Individuals tend to display different color patterns ranging from pure black to mottled black and blue, pink and white (Ref. 27829). Biparental open-spawning species (Ref. 52307).
IUCN Red List Status: Critically Endangered (CR); Date assessed: 01 March 2007 (B1ab(iii)+2ab(iii)) Ref. (130435)
Threat to humans:  harmless


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