Phylogenetic affinities of pygmy sunfishes (Elassoma) inferred from mitochondrial DNA sequences

Pygmy sunfishes (genus Elassoma) comprise six nominal species: three are co mmon and three are comparatively rare. Relationships of pygmy sunfishes to one another are not well known, in part because relationships of pygmy sunf ishes to other teleosts are controversial. We examined relationships of Ela ssoma to several putative sister groups suggested by previous comparative s tudies. Phylogenetic analysis of the mitochondrially encoded 12S rDNA (287 bp) and 16S rDNA (412 bp) genes did not unambiguously resolve relationships of Elassoma but did indicate alternative hypotheses that were consistent w ith molecular data. These include a sister-group relationship between Elass oma and Centrarchidae plus Moronidae. Alternatively, rDNA sequences are not consistent with hypothesized sister-group relationships between Elassoma a nd Atherinomorphs or Elassoma plus Cichlidae.