Actinopterygii (ray-finned fishes) > Osteoglossiformes
(Bony tongues) > Notopteridae
(Featherbacks or knifefishes)
Etymology: Xenomystus: Greek, xenos = strange + Greek, mystax = whiskered, used by Belon in 1553 to describe all fishes with whiskers (Ref. 45335).
Environment / Climate / Range
Freshwater; demersal; pH range: 6.0 - 8.0; dH range: 5 - 19. Tropical; 22°C - 28°C (Ref. 1672)
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 30.0 cm SL male/unsexed; (Ref. 31256)
Morphology | Morphometrics
soft rays: 108 - 130. Body height 5-5.4 x SL, head length 6.9-7.5 x SL, snout smaller than eye, eye diameter 3.8-4.5 x head length, maxilla extends to vertical of eye center or just under the eye's posterior border, ventral spines 25-32
Countries | FAO areas | Ecosystems | Occurrences | SELECT
scientificname = Xenomystus nigri
LIMIT 1Point map | Introductions | Faunafri
Africa: widely distributed in tropical Africa, in the Nile, Chad, Niger, Ogowe and Congo basins (Ref. 7431). Also distributed in coastal rivers in Sierra Leone, Liberia, Togo, Benin and Cameroon, but not found in Côte d'Ivoire nor Ghana (Ref. 7431).
Prefers quiet waters with vegetation. Females lay 150-200 eggs of 2 mm diameter (Ref. 1672). Can produce barking sounds. Comes to the surface from time to time to swallow air. Feeds at dusk and during the night on worms, crustaceans, insects and snails (Ref. 7020).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Roberts, T.R., 1992. Systematic revision of the old world freshwater fish family Notopteridae. Ichthyol. Explor. Freshwaters 2(4):361-383. (Ref. 7431)
IUCN Red List Status (Ref. 96402)
CITES (Ref. 94142)
Threat to humans
Fisheries: of no interest; aquarium: commercial
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 1.0010 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00851 (0.00323 - 0.02246), b=2.98 (2.76 - 3.20), based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.3 ±0.44 se; Based on food items.
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Low to moderate vulnerability (33 of 100) .