Astyanax ajuricaba: a new species from the Amazon basin in Brazil (Characiformes: Characidae)

Manoela M F Marinho,Flávio C T Lima

doi:10.1590/s1679-62252009000200006

Manoela M F Marinho, Flávio C T Lima

Open Access

https://doi.org/10.1590/s1679-62252009000200006

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Abstract

A new Astyanax species is described from several localities in the rio Negro, rio Solimões and lower rio Tapajós basins, Amazon basin, Brazil. The new species is distinguished from all remaining characids by its unique color pattern consisting of the combination of presence of a conspicuous, narrow dark midlateral stripe, a well-developed vertically-elongated dark humeral spot, and upper caudal-fin lobe and middle caudal-fin rays dark, with a rounded clear ocellated spot present at anterior third of caudal-fin lobe.

Highlights

Astyanax Baird & Girard is the most speciose characid genus, currently comprising more than 100 valid species
The genus is not diagnosed by apomorphies, but rather, is defined by a combination of features that are broadly distributed among Characidae
Géry (1992) noticed that, in spite of resembling the species of the Moenkhausia lepidura species complex, the undescribed Astyanax species possessed a high transversal scale count above lateral line when compared with specimens belonging to the Moenkhausia lepidura species complex, and, in addition, lack the typical scaled caudal-fin of Moenkhausia

Summary

Introduction

Astyanax Baird & Girard is the most speciose characid genus, currently comprising more than 100 valid species. The species described below was earlier reported by Géry (1992), based on a single specimen from the lago do Castanho (rio Solimões basin, Brazil), as a putative undescribed Astyanax species displaying a caudal-fin coloration unique within the genus, but shared with the Moenkhausia lepidura species complex: a dark mark on the upper caudal fin lobe. Géry (1992) noticed that, in spite of resembling the species of the Moenkhausia lepidura species complex, the undescribed Astyanax species possessed a high transversal scale count above lateral line when compared with specimens belonging to the Moenkhausia lepidura species complex, and, in addition, lack the typical scaled caudal-fin of Moenkhausia. Astyanax ajuricaba: A new species from the Amazon basin were identified at the MZUSP and MPEG collections. We describe this species, and provide remarks on its generic allocation

Material and Methods

Percents of head length

Findings

Literature Cited