A new species of Corydoras Lacépède (Siluriformes: Callichthyidae) from the Rio Tapajós basin and its phylogenetic implications

Vinicius C Espíndola,Marcelo R Britto,Marcelo R.S Spencer,Leandro R Rocha

doi:10.1590/0031-1049.2014.54.03

Abstract

A new species of Corydoras is described from tributaries of the rio Arinos, rio Teles Pires and rio Preto, all in the rio Tapajós basin. The new species is a member of a group that includes 36 species with spots on the body. Within this group, the new species can be readily distinguished by having a smaller dorsal-fin spine than the first three subsequent soft dorsal-fin rays; pectoral, pelvic and anal fins hyaline; dorsal-fin interradial membrane hyaline; rounded spots on trunk restricted to dorsolateral body plates and dorsal portion of ventrolateral body plates, not reaching the base of pelvic and anal fins. The new species can be further distinguished from Corydoras xinguensis by having spots with diffuse edges, and from all other species of spotted Corydoras except C.multimaculatus, by the absence of ventral platelets. A phylogenetic analysis recovered the new species plus Corydoras metae and C.araguaiensis in a clade sharing the presence of a pointed process on the maxilla for insertion of the retractor tentaculi muscle. In addition, the presence in the new species of an elongated anterior portion of the mesethmoid and a triangular uncinate process of the epibranchial 3 suggests a close relationship with Corydoras metae.

Highlights

Corydoras Lacépède is the most diversified catfish genus, currently including more than 160 valid species (Eschmeyer, 2013)
The species of Corydoras are widely distributed throughout cis-Andean South America in habitats such as shallow marginal areas of rivers, pools, and smaller tributaries (Reis, 2003)
Morphometric and meristic data were taken following Reis (1997), except for the length of the anal-fin spine, which is absent in all members of Corydoradinae

Summary

Introduction

Corydoras Lacépède is the most diversified catfish genus, currently including more than 160 valid species (Eschmeyer, 2013). The species of Corydoras are widely distributed throughout cis-Andean South America in habitats such as shallow marginal areas of rivers, pools, and smaller tributaries (Reis, 2003). Despite the huge diversity of shapes and color patterns among the species of Corydoras, the limits and definitions of a large amount of species are still unknown (Gosline, 1940; Nijssen & Isbrücker, 1980, 1986; Reis, 1998, 2003; Britto, 2003). 1. Universidade Federal do Rio de Janeiro, Museu Nacional, Departamento de Vertebrados, Setor de Ictiologia. Quinta da Boa Vista, s/n, São Cristóvão. CEP 20940‐040, Rio de Janeiro, RJ, Brasil

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