Actinopteri (ray-finned fishes) > Cyprinodontiformes
(Rivulines, killifishes and live bearers) > Rivulidae
(Rivulines) > Cynolebiinae
Etymology: Nematolebias: Greek, nema, -atos = filament + Greek, lebias, ou = a kind of small fish (Ref. 45335). More on author: Myers.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic; pH range: 6.5 - 7.0; dH range: 5 - 8; non-migratory; depth range - m (Ref. ), usually - m (Ref. ). Tropical; 20°C - 23°C (Ref. 1672)
South America: Laguna de Araruama basin, Das Ostras River basin, coastal plains adjacent to the mouth of São João River in Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 8.0 cm TL male/unsexed; (Ref. 36579)
Morphology | Morphometrics
soft rays: 18 - 24;
Vertebrae: 29 - 31. Having series of small bluish white spots, often coalesced to form continuous or fragmented line, on subdistal area of caudal fin and dark brown to black stripe on border of anal fin, adjacent and parallel to perpendicular extensions of subdistal golden transverse lines. Dorsal head profile slightly convex to nearly straight in male, gently concave to approximately straight in female (Ref. 42934).
Occurs in small freshwater temporary pools in floodplains of streams and lagoons. These pools are shallow with compact, soft reddish brown muddy bottom and dry twice a year, during winter, usually from July to August, and during summer, usually from February to March. During dry season, all fish die and eggs undergo in diapause within the substrate. Eclosion happens at the onset of wet season, usually March-April and September-October (Ref. 42934). This species was introduced in California (Ref. 4357). Bottom spawner, 4 months incubation. Is easy to maintain in the aquarium (Ref. 27139).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Males are territorial and very aggressive. Males display an elaborate courtship behavior beginning with waving lateral movement in front of female, with the unpaired fins completely opened. In an oblique position, the male touches the bottom surface with the anterior portion of its head, with vibrating body. The female placed her body side to side with the male. Then both couple dives into the substrates where spawning takes place (Ref. 42934).
Costa, W.J.E.M., 2002. The neotropical seasonal fish genus Nematolebias (Cyprinodontiformes: Rivulidae: Cynolebiatinae): taxonomic revision with description of a new species. Ichthyol. Explor. Freshwat. 13(1):41-52. (Ref. 42934)
IUCN Red List Status (Ref. 124695)
Threat to humans
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.6250 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00891 (0.00397 - 0.01999), b=3.14 (2.94 - 3.34), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.3 ±0.4 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): High, minimum population doubling time less than 15 months (tm=0.1).
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .