Redescrição de Astyanax saltor Travassos, 1960, uma espécie pouco conhecida da Serra do Cachimbo, Pará, Brasil (Characiformes: Acestrorphamphidae), com a descrição de novas espécies de Astyanax com faixa lateral escura

Abstract

Characiformes comprises approximately 280 genera and more than 2,300 species distributed among 24 families. Within this order, Acestrorhamphidae represents the most species-rich family, popularly known as tetras, lambaris and piabas, and exhibits remarkable morphological and ecological diversity, with nearly 1,300 valid species. The genus Astyanax is one of the most representative and widely distributed within the family, encompassing species that inhabit environments ranging from small headwater streams to large river systems, many of which remain poorly known from a scientific perspective. Among these species is Astyanax saltor, originally described in 1960 based on specimens collected in the Rio Cachimbo, Pará State, Brazil. Although the validity of the species has never been challenged, it lacks modern taxonomic studies that test this assumption and clearly delimit its taxonomic boundaries. Herein, Astyanax saltor is redescribed and diagnosed from its congeners based on meristic, morphometric, and coloration characters. The species is proposed as endemic to the rio Braço Norte basin, a tributary of the rio Teles Pires, in Pará State. In addition, several morphotypes from neighboring regions previously identified as Astyanax saltor were examined; these are described herein and proposed as potential new species.