''Simpsonichthys nielseni'' is a species of

killifish A killifish is any of various oviparous (egg-laying) cyprinodontiform fish (including families Aplocheilidae, Cyprinodontidae, Fundulidae, Profundulidae and Valenciidae). All together, there are 1,270 species of killifish, the biggest famil ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Rivulidae The Rivulidae are a family of killifishes in the order Cyprinodontiformes. They are commonly known as rivulids, South American killifish or New World killifish. The latter names are slightly misleading, however, as they are neither restricted to ...

. It is found in the

São Francisco River The São Francisco River (, ) is a large 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, the Paraná and t ...

basin, Brazil.

References

nielseni Fish of the São Francisco River basin Taxa named by Wilson José Eduardo Moreira da Costa Fish described in 2005 {{Rivulidae-stub