Table of Contents
International Journal of Evolutionary Biology
Volume 2012 (2012), Article ID 915265, 8 pages
http://dx.doi.org/10.1155/2012/915265
Research Article

Deep Phylogenetic Divergence and Lack of Taxonomic Concordance in Species of Astronotus (Cichlidae)

1Laboratório de Evolução e Genética Animal (LEGAL), Universidade Federal do Amazonas (UFAM), 69077-000 Manaus, AM, Brazil
2Departamento de Genética e Evolução, Universidade Federal de São Carlos (UFSCar), 18052-780 São Carlos, SP, Brazil

Received 28 January 2012; Accepted 14 April 2012

Academic Editor: Martin J. Genner

Copyright © 2012 Olavo Pinhatti Colatreli et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The neotropical cichlid genus Astronotus currently comprises two valid species: A. ocellatus Agassiz, 1831 and A. crassipinnis Heckel, 1840. The diagnosis is based on color pattern and meristics counts. However, body color pattern is highly variable between regions and the meristic counts show a considerable overlap between populations differing in color patterning. They do not represent true synapomorphies that diagnose species. Purportedly the only truly diagnostic character is the presence or absence of one or more ocelli at the base of the dorsal fin, diagnosing A. ocellatus and A. crassipinnis, respectively. Using the portion of the mitochondrial COI gene and EPIC nuclear markers, the validity of the dorsal ocelli as diagnostic character was tested in individuals sampled from ten localities in the Amazon basin. Analyses rejected the hypothesis that dorsal ocelli are diagnostic at the species level. However, they revealed the existence of five hypothetical, largely allopatrically distributed morphologically cryptic species. The phylogeographic structure is not necessarily surprising, since species of the genus Astronotus have sedentary and territorial habits with low dispersal potential. The distribution of these hypothetical species is coincident with patterns observed in other Amazonian aquatic fauna, suggesting the role of common historical processes in generating current biodiversity patterns.