Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Cichlidae
(Cichlids) > Pseudocrenilabrinae
Etymology: Tylochromis: Greek, tylos = callus + Greek, chromis = a fish, perhaps a perch (Ref. 45335); aristoma: ari = Greek for well-developed, stoma = Greek for mouth (Ref. 52307). Named in reference to the prominent lower jaw and large-mouthed appearance of the adult (Ref. 52346).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
Africa: restricted to the Ruki River drainage (middle Congo River basin), in Democratic Republic of the Congo (Ref. 52346, 93897).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 19.3 cm SL male/unsexed; (Ref. 5714)
Morphology | Morphometrics
(total): 13 - 16;
soft rays: 7;
Vertebrae: 28 - 29. Diagnosis: deep bodied, robust species with a relatively large mouth (compared to its congeners), but juveniles slender (Ref. 52307). Slender gracile lower jaw and narrow elongate keel (Ref. 52346). Dorsum strongly curved from nape to caudal peduncle but ventrum more or less flattened; long snout with a straight and steep predorsal profile passing uninterrupted to origin of dorsal fin, where body depth is largest; lower jaw extremely prominent; lips well-formed but not overly thickened or fleshy; entire premaxillary oral flap present; buccal teeth capped with brown or black enameloid; in juveniles all teeth small and fine with little differentiation in tooth size between inner and outer rows; in adult (male) teeth coarse and enlarged; upper branch of lateral line terminates in advance of end of dorsal fin; dorsal, ventral and medial lateral line branches on caudal fin well developed and almost reach to periphery; dorsal fin spines increase in length to 4th-5th and are then more or less of equal length; anal fin rounded; caudal fin roundly emarginate and densely scaled; pectoral fin relatively elongate and usually reaches level of first soft anal ray; first branched pelvic ray produced and filamentous (Ref. 52346).
Coloration: adult male: upper lip and front of head black (Ref. 52307, 52346). Just anterior to a short black nape stripe a patch of red/gold is present (Ref. 52346). Cheeks, operculum and breast silvery-white with greenish iridescent parts (Ref. 52307). Just behind nape band a broad pale blue/green band extends obliquely down to base of pelvic fins (Ref. 52346). Behind this oblique band body dark (golden) bronze which becomes more greenish towards caudal peduncle (Ref. 52307, 52346). Darker pigmentation on flank scales; dorsal, pelvic and anal fins dark reddish brown, with numerous rows of small greenish dots (Ref. 52307). Caudal fin light brown centrally, with more reddish parts in distal (outer) regions and many small black lines (Ref. 52307, 52346). (Preserved) juveniles: ground coloration light brown with dark smokey grey upper lip and front of head; nape band strongly marked but not reaching down onto operculum; diffuse opercular blotch present on lower portion of operculum; 6 vertical stripes extend down well below midline and onto belly and ventrum (especially in the smallest specimens) (Ref. 52346).
Seems to feed primarily upon plants and insect larvae; maternal mouthbrooder that does not pair-bond (Ref. 52307).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Stiassny, M.L.J., 1991. Tylochromis. p. 526-533. In J. Daget, J.-P. Gosse, G.G. Teugels and D.F.E. Thys van den Audenaerde (eds.) Check-list of the freshwater fishes of Africa (CLOFFA). ISNB, Brussels; MRAC, Tervuren; and ORSTOM, Paris. Vol. 4. (Ref. 5714)
IUCN Red List Status (Ref. 120744)
CITES (Ref. 115941)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 2.7 ±0.3 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Low to moderate vulnerability (26 of 100) .