Bayesian analyses detect a history of both vicariance and geodispersal in Neotropical freshwater fishes

The program phase is widely used for Bayesian inference of haplotypes from diploid genotypes; however, manually creating phase input files from sequence alignments is an error-prone and time-consuming process, especially when dealing with numerous variable sites and/or individuals. Here, a web tool called seqphase is presented that generates phase input files from fasta sequence alignments and converts phase output files back into fasta. During the production of the phase input file, several consistency checks are performed on the dataset and suitable command line options to be used for the actual phase data analysis are suggested. seqphase was written in perl and is freely accessible over the Internet at the address http://www.mnhn.fr/jfflot/seqphase. © 2009 Blackwell Publishing Ltd.

Background With nearly 1,100 species, the fish family Characidae represents more than half of the species of Characiformes, and is a key component of Neotropical freshwater ecosystems. The composition, phylogeny, and classification of Characidae is currently uncertain, despite significant efforts based on analysis of morphological and molecular data. No consensus about the monophyly of this group or its position within the order Characiformes has been reached, challenged by the fact that many key studies to date have non-overlapping taxonomic representation and focus only on subsets of this diversity. Results In the present study we propose a new definition of the family Characidae and a hypothesis of relationships for the Characiformes based on phylogenetic analysis of DNA sequences of two mitochondrial and three nuclear genes (4,680 base pairs). The sequences were obtained from 211 samples representing 166 genera distributed among all 18 recognized families in the order Characiformes, all 14 recognized subfamilies in the Characidae, plus 56 of the genera so far considered incertae sedis in the Characidae. The phylogeny obtained is robust, with most lineages significantly supported by posterior probabilities in Bayesian analysis, and high bootstrap values from maximum likelihood and parsimony analyses. Conclusion A monophyletic assemblage strongly supported in all our phylogenetic analysis is herein defined as the Characidae and includes the characiform species lacking a supraorbital bone and with a derived position of the emergence of the hyoid artery from the anterior ceratohyal. To recognize this and several other monophyletic groups within characiforms we propose changes in the limits of several families to facilitate future studies in the Characiformes and particularly the Characidae. This work presents a new phylogenetic framework for a speciose and morphologically diverse group of freshwater fishes of significant ecological and evolutionary importance across the Neotropics and portions of Africa.