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International Journal of Ecology
Volume 2012 (2012), Article ID 610419, 20 pages
http://dx.doi.org/10.1155/2012/610419
Research Article

Ecological Factors and Diversification among Neotropical Characiforms

1Facultad de Ciencias, Universidad de Vigo, Lagoas-Marcosende, 36200 Vigo, Spain
2Grupo de Ictiología, Universidad de Antioquia, A.A. 1226, Medellín, Colombia
3Departamento de Xenética, Facultade de Veterinaria, Universidade de Santiago de Compostela, Campus de Lugo, Avenida Carballo Calero s/n 27002 Lugo, Spain
4Instituto Amazónico de Investigaciones (IMANI), Universidad Nacional de Colombia, Km 2 vía Tarapacá, Leticia, Colombia
5Instituto de Biología, Universidad de Antioquia, A.A. 1226, Medellín, Colombia
6National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, MRC 159, Washington, DC, USA
7Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes s/n, 41012-Sevilla, Spain

Received 25 August 2011; Revised 4 December 2011; Accepted 31 January 2012

Academic Editor: J. J. Wiens

Copyright © 2012 Cástor Guisande 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

Morphological and DNA sequence data has been used to propose hypotheses of relationships within the Characiformes with minimal comparative discussion of causes underpinning the major intraordinal diversification patterns. We explore potential primary morphological factors controlling the early diversification process in some Neotropical characiforms as the first step to identifying factors contributing to the pronounced intraordinal morphological and species diversity. A phylogenetic reconstruction based on 16S rDNA (mitochondrial) and 18S rDNA (nuclear) genes provided the framework for the identification of the main morphological differences among the Acestrorhynchidae, Anostomidae, Characidae, Ctenoluciidae, Curimatidae, Cynodontidae, Gasteropelecidae, Prochilodontidae and Serrasalmidae. Results indicate an initial split into two major groupings: (i) species with long dorsal-fin bases relative to the size of other fins (Curimatidae, Prochilodontidae, Anostomidae, Serrasalmidae) which primarily inhabit lakes, swamps, and rivers (lineage I); and (ii) species with short dorsal-fin bases (Acestrorhynchidae, Gasteropelecidae, Characidae) which primarily inhabit creeks and streams (lineage II). The second diversification stage in lineage I involved substantial morphological diversification associated with trophic niche differences among the monophyletic families which range from detritivores to large item predators. Nonmonophyly of the Characidae complicated within lineage II analyzes but yielded groupings based on differences in pectoral and anal fin sizes correlated with life style differences.