Actinopterygii (ray-finned fishes) > Gonorynchiformes
(Milkfish) > Kneriidae
Etymology: Kneria: From Kner, that studied fishes in the Imperial Museum of Vienna, with Jean Natterer (1817) (Ref. 45335); rukwaensis: Refers to the Lake Rukwa basin, Tanzania and Zambia, where the center of distribution of the species is situated; an adjective (Ref. 26644).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; demersal. Tropical; ? - 20°C (Ref. 27292)
Africa: restricted to the western drainage of the Lake Rukwa system and to the upper Kalambo drainage (Tanganyika basin) in Tanzania and Zambia (Ref. 26644).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 6.2 cm SL male/unsexed; (Ref. 26644)
soft rays: 9 - 11. Diagnosis: dorsal fin origin behind pelvic fin origin; 96-104 lateral line scales; preanal length 70.7-76.2% SL; prepelvic length 46.7-52.6% SL; 9-11 anal fin rays (Ref. 26644). Lower lobe of caudal fin longer and narrower than upper lobe in fully adult males (Ref. 26644, 27292), the upper lobe as long as the proximal part of the caudal fin (Ref. 27292). Opercular disc of males characteristic, its posterior margin broad, and postopercular apparatus well developed and pillow-like (Ref. 26644).
Maximum total length recorded is 7.44cm TL (Ref. 26644). Mostly found in stagnant pools and moderately flowing streams, only rarely in fast flowing currents; omnivorous; a female of 6.55cm TL releases about 400-500 ripe eggs of a diameter of 1.2mm (Ref. 27292). Apparently no marked spawning period (Ref. 44637). Male reported to change its coloration at night, being very pale with dark spots along the midline of the body (Ref. 27292).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Seegers, L., 1995. Revision of the Kneriidae of Tanzania with description of three new Kneria species (Teleostei: Gonorhynchifromes). Ichthyol. Explor. Freshwat. 6(2):97-128. (Ref. 26644)
IUCN Red List Status (Ref. 119314)
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
= 0.5001 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00389 (0.00180 - 0.00842), b=3.12 (2.94 - 3.30), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months ().
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .