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); polli: Named after Dr. Max Poll, who first recognized the opercular apparatus of Xenopomatichthys to be a character of the mature male, and not generic (Ref. 42110). More on author: Trewavas.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical; 10°S - 17°S
Africa: rivers Cuvo and Cubal in Angola (Ref. 11970), possibly also in other coastal rivers in Angola (Ref. 52193). Also in the upper reaches of the upper Zambezi, Okavango and Kunene in Angola and Zambia (Ref. 52193), and the Kafue in Zambia (Ref. 13332). Presence in the upper Congo river basin (Ref. 41590, 52959) considered questionable in Ref. 2970. Not yet captured in Namibia (Ref. 33857).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 7.0 cm SL male/unsexed; (Ref. 52193)
soft rays: 10 - 12. Diagnosis: body depth 5.5-6.6 times in standard length (SL); head length 4.75-5.25 times in SL (Ref. 11970, 42110). Head width a little less than head depth at occipital region, 1.75-2 times in head length (HL) (Ref. 42110). Snout 3-3.4 times in HL; eye diameter 3.4-4.17 times in HL; interorbital width 2.75-3.4 times in HL; eyes lateral (Ref. 11970, 42210). Mature males with cupped outgrowth on operculum and a series of oblique laminae behind gill-opening (Ref. 11970, 42110), and without spines on head (Ref. 42110). Dorsal fin origin equidistant from tip of snout and base of caudal (Ref. 11970, 13721, 42110) or nearer mid-base of caudal than tip of snout (Ref. 7248, 52193), above (Ref. 42110) or immediately behind base of pelvic (Ref. 11970, 13721, 42110). Anal fin base equidistant from origin of pelvic and root of caudal (Ref. 42110), or a little nearer caudal (Ref. 11970, 42110). Pectoral fin length 5/6 of head length (Ref. 42110) or nearly as long as head (Ref. 11970, 42110). Pelvic fin as long as or a little shorter than pectoral (Ref. 42110). Caudal peduncle 1.9-2.1 times as long as deep (Ref. 11970, 42110). Body yellowish, with a series of dark spots, united by a narrower band, along lateral line or its posterior 2/3; a series of 3-5 round dark spots on either side of middorsal line in front of dorsal fin; sometimes a spot at origin of dorsal; fainter dark markings along back and side; upper part of head dark, lower parts of head and trunk pale; caudal fin spotted or clear, other fins clear (Ref. 42110). Dark spots at bases of pectoral, ventral and anal fins (Ref. 13721), but no dark spot at base of pelvic fins of type specimens (Ref. 7248, 52193).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Poll, M., 1984. Kneriidae. p. 129-133. In J. Daget, J.-P. Gosse and D.F.E. Thys van den Audenaerde (eds.) Check-list of the freshwater fishes of Africa (CLOFFA). ORSTOM, Paris and MRAC, Tervuren. Vol. 1. (Ref. 3565)
IUCN Red List Status (Ref. 115185)
CITES (Ref. 115941)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg 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) .