Oreochromis malagarasi Trewavas, 1983
Malagarasi tilapia
photo by RMCA

Family:  Cichlidae (Cichlids), subfamily: Pseudocrenilabrinae
Max. size:  27 cm TL (male/unsexed)
Environment:  benthopelagic; freshwater
Distribution:  Africa: Malagarasi River and marginal waters of Lake Tanganyika near Kigoma in Tanzania (Ref. 118638) and Burundi (Ref. 54847).
Diagnosis:  Dorsal spines (total): 16-17; Dorsal soft rays (total): 12-13; Anal spines: 3-3; Anal soft rays: 10-12; Vertebrae: 29-30. Diagnosis: A large bodied Oreochromis, characterised by a deep body, short snout and 3-4 blotches on the flank coupled with around 6 faint wide vertical bars (Ref. 118638). It is a tasselled species, resembling Oreochromis upembae from which it differs in the following features: mid-lateral blotches present as in O. upembae, caudal fin either without spots or with a few irregularly arranged or in quincunx; caudal rays variously scaly but the inter-radial membranes usually free of scales; vertebrae 29-30; scales in lateral line series 30-32; dorsal spines XVI-XVII, soft rays 12-13; and outer teeth mainly bicuspid, but often including a few tricuspids (Ref. 2). With grey/green fins and flanks; male dorsal and caudal fins have red/orange margins; ripening males reported to be dark green-grey, possibly almost black (Ref. 118638). Description: A relatively shallow-bodied fish, with a pointed snout and a straight frontal profile; and a correspondingly deep caudal peduncle (Ref. 2, 52307). Gill-rakers 3-4,1,20-24 on first arch (Ref. 2). The length of the lower pharyngeal bone is greater than its width and 33-38% length of head; the blade is as long as the median length of the toothed part in a fish of 125.5 mm standard length, to 1.4 times as long in a 172 mm fish; the pharyngeal teeth are slender, those of four posterior rows brown-tipped and bicuspid, the anterior are more crowded (Ref. 2). The mouth is small and there is no difference correlated with age or sex; the teeth are in 4-6 rows in each jaw, with slender shafts; several specimens have a few tricuspids among the bicuspid outer teeth; inner tricuspid (Ref. 2). Scales on cheek in 2 rows; 4-6.5 between origin of dorsal and lateral line (Ref. 2). The genital papilla is bifid in females and males (Ref. 2). Colouration: Living colouration remains unknown (Ref. 52307). Preserved specimens exhibit dark maculae in the center of the body; the caudal fin exhibits some pale maculae (Ref. 52307).
Biology:  Inhabits rivers and swamps (Ref. 4967). It feeds on the soft, flocculent bottom deposits, which consisted of finely divided plant material and many protozoa, bacteria, algae and detritus (Ref. 2, 52307); the young were feeding on fish offal near canoe-landings (Ref. 2). A maternal mouthbrooder (Ref. 118638). A locally important species in artisanal fisheries (Ref. 118638); it contributes to swamp fishery (Ref. 4967). Recorded from aquaculture ponds near Kigoma (Ref. 118638).
IUCN Red List Status: Not Evaluated (N.E.) Ref. (130435)
Threat to humans:  harmless


Source and more info: www.fishbase.org. For personal, classroom, and other internal use only. Not for publication.