''Simpsonichthys alternatus'' is a species of

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 ...

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, ...

. It is found in the

São Francisco River The São Francisco River (, ) is a large Rivers of Brazil, river in Brazil. With a length of , it is the longest river that runs entirely in Brazilian territory, and the fourth longest in South America and overall in Brazil (after the Amazon R ...

basin, Brazil.

Description

''Simpsonichthys alternatus'' reaches a

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

of .

References

*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 alternatus Taxa named by Wilson José Eduardo Moreira da Costa Taxa named by Gilberto Campello Brasil Fish described in 1994 {{Rivulidae-stub