Phylogenetic Relationships of Species of the Genus Brachyrhaphis ( Poeciliidae ) Inferred from Partial Mitochondria 1 DNA Sequences

Phylogenetic relationships were reconstructed using partial mitochondrial DNA sequence data for the cytochrome b gene among all nine described species of Bra&flaphis and several members of the tribe Gambusiini. We included three of the more than 40 members of the genus Gambusia and Belonesox belimnus, the third, monotypic genus of the tribe Gambusiini. Xiphophorus malinche served as the outgroup. Phylogenetic trees were generated using maximum-parsimony, maximumlikelihood, and neighbor-joining analyses. Hypotheses of relationships withii the tribe and genus Brachyrhaphis made by previous authors were tested. The existence of a slimand a deep-bodied clade within the monophyletic genus BraFhflaphis was supported. Bmchyrhaphis hariwegi is the basal member of the deep-bodied clade, whereas B. punctifer is the basal member of the slim-bodied clade.