''Spectrolebias'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of killifish in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Rivulidae The Rivulidae are a family (biology), family of killifishes in the order (biology), order Cyprinodontiformes. They are commonly known as rivulids, South American killifish or New World killifish. The latter names are slightly misleading, however, ...

. These annual

killifish A killifish is any of various oviparous (egg-laying) cyprinodontiform fish, including families Aplocheilidae, Pantanodontidae, Cyprinodontidae, Fundulidae, Nothobranchiidae, Profundulidae, Aphaniidae and Valenciidae. All together, there ar ...

are

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to seasonal waters (like pools) in the

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

Tocantins Tocantins () is one of the 26 states of Brazil. It is the newest state, formed in 1988 and encompassing what had formerly been the northern two-fifths of the state of Goiás. Tocantins covers and had an estimated population of 1,496,880 in 2014 ...

– Araguaia, Xingu and Mamoré– Grande basins in Bolivia, Brazil and Paraguay.Nielsen, D.T.B. & Pillet, D. (2015): ''Spectrolebias bellidoi'', a new annual fish (Cyprinodontiformes: Rivulidae: Cynolebiatinae) from the upper Río Grande basin, Amazon basin, Bolivia. ''aqua, International Journal of Ichthyology, 21 (4): 180-187.''Nielsen, D.T.B. & Brousseau, R. (2013): ''Spectrolebias pilleti'', a new annual Killifish (Cyprinodontiformes: Rivulidae: Cynolebiatinae) from the upper río Mamoré basin, Bolivia. ''aqua, International Journal of Ichthyology, 19 (3): 115-122.'' Each species generally has a small distribution and some are seriously threatened by

habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

; the entire known range of ''S. reticulatus'' is in the area flooded by the

Belo Monte Dam The Belo Monte Dam (''formerly known as'' Kararaô) is a hydroelectric dam complex on the northern part of the Xingu River in the state of Pará, Brazil. After its completion, with the installation of its 18th turbine, in November 2019, the in ...

. They are small fish, up to in

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

. As typical of killifish, males are more colorful than females.

Species

''Spectrolebias'' was formerly regarded as a subgenus of ''

Simpsonichthys ''Simpsonichthys'' is a genus of killifish from the Family (biology), family Rivulidae the species of which are Endemism, endemic to temporary freshwater habitats like ponds in the upper Paraná River, Paraná, upper Araguaia River, Araguaia, upp ...

''. Although this split is generally accepted, a genetic study indicates that ''Spectrolebias'' is not

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

. There are currently 9 recognized species in ''Spectrolebias'': * '' Spectrolebias bellidoi'' D. T. B. Nielsen & Pillet, 2015 * '' Spectrolebias brousseaui'' D. T. B. Nielsen, 2013 * '' Spectrolebias chacoensis'' ( L. H. Amato, 1986) * '' Spectrolebias costai'' ( Lazara, 1991) * '' Spectrolebias filamentosus'' ( W. J. E. M. Costa, Barrera &

Sarmiento Sarmiento may refer to: Places Argentina *Sarmiento Department, San Juan, a subdivision of the San Juan Province * Sarmiento Department, Santiago del Estero, a subdivision of the Santiago del Estero Province * Sarmiento Department, Chubut, a subdi ...

, 1997) * '' Spectrolebias inaequipinnatus'' ( W. J. E. M. Costa & G. C. Brasil, 2008) * '' Spectrolebias pilleti'' D. T. B. Nielsen & Brousseau, 2013 * '' Spectrolebias reticulatus'' ( W. J. E. M. Costa & D. T. B. Nielsen, 2003) * '' Spectrolebias semiocellatus'' W. J. E. M. Costa & D. T. B. Nielsen, 1997

References

{{Taxonbar, from=Q21346850 Rivulidae Freshwater fish genera