Actinopterygii (ray-finned fishes) > Characiformes
(Characins) > Distichodontidae
Etymology: Eugnathichthys: Greek, eu = good + Greek, gnathos = jaw + Greek, ichthys = fish (Ref. 45335); virgatus: This species is named virgatus, from the Latin, in reference to the conspicuous midlateral band or streak forming the characteristic pigmentation patterning of the species in life and in preservation (Ref. 94471).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
Africa: middle Congo River basin, in the Sangha, Lulonga, Ruki (Ref. 94471), Itimbiri and Aruwimi (Ref. 106290), in Republic of Congo and Democratic Republic of the Congo. Possibly also in the Ubangi (Ref. 94471).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 10.6 cm SL male/unsexed; (Ref. 94471)
Morphology | Morphometrics
soft rays: 11 - 12;
Vertebrae: 42 - 43. Diagnosis: Eugnathichthys virgatus is unique among congeners in the possession of body pigmentation dominated by a broad lateral band intersected by numerous vertical bars resulting in a midlateral, checkerboard-like pigmentation patterning both in life and in preservation (Ref. 94471). Internally it is characterized by a marked reduction in dentition on the fifth ceratobranchial elements of the pharynx; externally it differs from congeners in the possession of a reduced total number of pectoral-fin rays, 13-15 vs. 16-18 (Ref. 94471). Eugnathichthys virgatus is further readily distinguished from E. eetveldii by the possession of 66-72 pored lateral line scales from opercle to caudal flexion vs. 96-103; 10-12 scale rows between the lateral line and the dorsal-fin origin vs. 14 or 15; and 8 or 9 scale rows between the lateral line and pelvic-fin insertion vs. 10 (Ref. 94471).It differs from E. macroterolepis in the possession of 8 or 9 scale rows between the lateral line and the pelvic-fin insertion vs. 6 or 7 (Ref. 94471).
This species lives in heavily shaded, highly humic forest rivers (Ref. 94471). Gut morphology and contents suggest that the species feeds exclusively on fish fins (Ref. 94471).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Stiassny, M.L.J., J.S.S. Denton and Monsembula Iyaba R.J.C., 2013. A new ectoparasitic distichodontid of the genus Eugnathichthys (Characiformes: Citharinoidei) from the Congo basin of central Africa, with a molecular phylogeny for the genus. Zootaxa 3693(4):479-490. (Ref. 94471)
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
= 0.6250 [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
): 3.0 ±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) .