A new species of Bryconops (Teleostei: Characidae) from the rio Madeira basin, Northern Brazil

Juliana M Wingert,Luiz R Malabarba

doi:10.1590/s1679-62252011000300002

Abstract

A new species of Bryconops is described from a tributary to the rio Madeira in the Amazon basin, State of Rondônia, Brazil. Bryconops piracolina belongs to the subgenus Bryconops by having no teeth or rarely one tooth in the maxilla, and a naked area on cheek between the second and third infraorbitals. The new species is distinguished from all species of this subgenus by the presence of a large black blotch on dorsal-fin base. Furthermore, it is distinguished from all congeners, except B. inpai, by possessing the adipose fin entirely black. It differs from B. inpai by the lack of humeral spots. It further differs from all species of the subgenus Bryconops, except B. caudomaculatus, by having the last scales of the longitudinal series of scales that bears the lateral line series not pored beyond the end of the hypural plate, and differs from B. caudomaculatus by the smaller number of pored lateral line scales (31-36, mean 34.6, vs. 37-43, mean = 40.6, respectively).

Highlights

Bryconops Kner, 1858 is a relatively small cis-Andean genus of the Characidae including 18 valid species (Lima et al, 2003; Chernoff & Machado-Allison, 2005) distributed in the coastal rivers of northern Brazil and Guyana, and in the Orinoco, Amazonas, Tocantins, Paraguay, and São Francisco river basins
In this paper we describe a new species of Bryconops, subgenus Bryconops, as defined by Chernoff & Machado-Allison (1999, 2005) from the rio Madeira basin, rio Amazonas drainage, in the State of Rondônia, Brazil
The new species further lacks the synapomorphies proposed by Chernoff & Machado-Alisson (1999) for the subgenus Creatochanes, including the posterior extension of the maxilla reaching to the junction between the second and third infraorbitals, and the second infraorbital contacting the third infraorbital without an intervening naked area on the cheek

Summary

Introduction

Bryconops Kner, 1858 is a relatively small cis-Andean genus of the Characidae including 18 valid species (Lima et al, 2003; Chernoff & Machado-Allison, 2005) distributed in the coastal rivers of northern Brazil and Guyana, and in the Orinoco, Amazonas, Tocantins, Paraguay, and São Francisco river basins. The genus has been considered relatively basal in the Characidae in possessing a supraorbital bone that is absent in the representatives of most small-sized characids (Malabarba & Weitzman, 2003) Such a basal position was further supported by Mirande (2010) who listed fourteen synapomorphies in addition to the lack of a supraorbital bone in defining a large clade containing most small-sized characids and excluding Bryconops. The species in the genus are currently divided among two subgenera, Bryconops and Creatochanes Günther, 1864. These were treated as monophyletic by Chernoff & Machado-Allison (1999) and in subsequent papers. In this paper we describe a new species of Bryconops, subgenus Bryconops, as defined by Chernoff & Machado-Allison (1999, 2005) from the rio Madeira basin, rio Amazonas drainage, in the State of Rondônia, Brazil

Material and Methods

Results

H Range Mean SD

Discussion

Literature Cited