Actinopterygii (ray-finned fishes) > Characiformes
(Characins) > Alestidae
Etymology: Bryconaethiops: Greek, bryko = to bite+ Aethiops, region in North east Africa (Ref. 45335); yseuxi: Named after Dr. E. Yseux, professor at the Université Libre de Bruxelles (Ref. 74421). More on author: Boulenger.
This species is a synonym of Bryconaethiops microstoma Günther, 1873 in Eschmeyer (CofF ver. May 2011: Ref. 86870).
Environment / Climate / Range
Freshwater; pelagic. Tropical, preferred ?
Africa: from Boma on the lower Congo River up to Pool Malebo, in Republic of Congo and Democratic Republic of the Congo basin (Ref. 74421).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 7.2 cm SL male/unsexed; (Ref. 74421)
Morphology | Morphometrics
soft rays: 21 - 23. Bryconaethiops yseuxi can be distinguished from all other known Bryconaethiops species based on the following unique combination of characters: a high number of scale rows between anterior origin of dorsal fin and lateral line (7.5 vs. 6.5 or less); a low number of gill rakers on the first gill arch; and a long dorsal-fin and anal-fin bases, respectively 15.7-17.6% and 22.7-25.9% of standard length (Ref. 74421). Body deep and somewhat laterally compressed (Ref. 74421). Mouth terminal; upper jaw with three rows of premaxillary teeth; external row composed of two small median teeth with a small lateral cusp at their outer side; a median row with 6 or 7 teeth; and an inner row of 8 pluricuspid teeth with their cusp on a median row and without an anterior cusp or row of cusps as generally found in the other Bryconaethiops species (Ref. 74421). Lower jaw with an external series of 6 large pluricuspid teeth and an inner row of two median caniniform teeth (Ref. 74421). Lateral line scales 34-39; longitudinal line scales 36-40 (Ref. 74421). Head and body of live mature male specimens silvery with a pinkish hue on sides of the body; upper side of head green-olive; humeral spot present but not well marked; adipose-fin whitish transparent, blackish at base (Ref. 74421). After preservation, body yellowish white; darker above lateral line with scales above lateral line faintly dark brown on their basal part; fins whitish, transparent in overall appearance; humeral spot not well distinguishable, or even regularly absent (Ref. 74421).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Ibala Zamba, A., G. De Boeck, V. Mamonekene and E. Vreven, 2007. Rehabilitation of Bryconaethiops yseuxi Boulenger, 1899 (Characiformes: Alestidae) from the Congo River basin, Africa. J. Nat. Hist. 41(17-20):1213-1226. (Ref. 74421)
IUCN Red List Status (Ref. 109396)
CITES (Ref. 94142)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5312 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01122 (0.00512 - 0.02461), b=3.00 (2.81 - 3.19), based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.1 ±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 vulnerability (10 of 100) .