Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Actinopteri (ray-finned fishes) > Cyprinodontiformes
(Rivulines, killifishes and live bearers) > Rivulidae
(Rivulines) > Kryptolebiatinae
Etymology: More on author: Poey.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; brackish; benthopelagic; pH range: ? - 7.5; dH range: ? - 16; non-migratory; depth range 0 - ? m (Ref. 55170). Tropical; 18°C - 24°C (Ref. 2060); 31°N - 3°N, 93°W - 49°W (Ref. 55170)
North, Central and South America: eastern coasts of Florida (Indian River to Key West) in USA and Bahamas to Cuba, Jamaica, Cayman Island, Brazil, French Guiana, the Netherlands Antilles, Venezuela, Belize, Mexico, Puerto Rico. Throughout Caribbean (Ref. 26938).
Length at first maturity / Size / Weight / Age
Maturity: Lm 17.0  range ? - ? cm
Max length : 7.5 cm TL male/unsexed; (Ref. 27139)
Dark spot surrounded by yellow ring on side of caudal peduncle, just ahead of upper part of caudal fin base (Ref. 26938).
Facultative air-breathing (Ref. 126274); Adults inhabit shallow, mud-bottomed ditches, bays, salt marshes and other brackish-water environments; also crab burrows (Ref. 5723), moist leaf litter, decaying mangrove logs (Ref. 93034). Can withstand heavy pollution of fresh or salty waters and shares its biotope with Poecilia vivipara which is much more abundant (Ref. 35237). Usually found in water with low oxygen content (Ref. 7251). Either male or hermaphroditic, females don't seem to exist. Only about 5% of a population are born as males; after 3-4 years about 60% of the (self-fertilizing) hermaphrodites transform into secondary males by losing female structure and function. The proportion of males depends on the environmental temperature. Below 20°C, majority are males, above 25°C all are hermaphrodites (Ref. 35237). It is the only known naturally occurring, self-fertilizing vertebrate (Ref. 13056, 35237). Not a seasonal killifish. Is very difficult to maintain in aquarium (Ref. 27139).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Eggs are sometimes fertilized internally by accident via close apposition of gonopores in otherwise oviparous fishes (Ref. 7471). Regarded as a self-fertilizing hermaphrodite (Ref. 6028, 245, 35237). Eggs are 1.6 mm in diameter. Sexes can be distinguished after 8 weeks (Ref. 35237). Also Ref. 103751.
Costa, W.J.E.M., 2003. Rivulidae (South American Annual Fishes). p. 526-548. In R.E. Reis, S.O. Kullander and C.J. Ferraris, Jr. (eds.) Checklist of the Freshwater Fishes of South and Central America. Porto Alegre: EDIPUCRS, Brasil. (Ref. 36579)
IUCN Red List Status (Ref. 125652)
Threat to humans
Aquarium: commercial; bait:
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82804
= 0.5039 [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
Trophic level (Ref. 69278
): 3.2 ±0.48 se; based on food items.
Resilience (Ref. 120179
): High, minimum population doubling time less than 15 months (tm=0.5).
Fishing Vulnerability (Ref. 59153
): Low vulnerability (10 of 100).