Distribution and taxonomic identity of the species of Narcine (Toperdiniformes: Narcinidae) in the southwestern Atlantic Ocean.

Abstract

The genus Narcine is the most diverse among electric rays of the order Torpediniformes and is also the only electric ray genus with more than one species occurring in South American waters: Narcine brasiliensis and Narcine bancroftii. The first species has been historically described as distributed from Brazil's southeast coast down to northern Argentina, whereas the latter is distributed from northern South America to Central America, and the southernmost coast of North America. This revision of occurrences of the genus for the coast of Brazil, with focus on the northeast region, expands the range of distribution of both species. These species were previously considered to have very distinct areas of occurrence but actually present some degree of overlap on their distributional areas, with the northeast coast of Brazil acting as the intersection of both species' range of occurrence. Additionally, this study discusses the diagnostic characteristics for identifying Narcine species and highlights the historical scientific bias surrounding this group and how it ultimately can lead to a misrepresentation of its geographic distribution and conservation status.