Comparative mitochondrial genomics of tetras: insights into phylogenetic relationships in Characidae

Although classical morphological classification within the Characidae has long history, this taxonomic perspective is now challenged when using mitochondrial genes to investigate phylogeny of this family. We discovered the problems of classical taxonomic systems from the point of mitochondrial genome of Characidae species. Here, six newly sequenced complete mitogenomes of Characidae (H. armstrongi, H. ocellifer, H. amapaensis, H. anisitsi, H. socolofi, and P. riddlei) are presented. The six mitogenomes were all typical circular molecule, with total lengths ranging from 16,789 to 18,141 bp. Base composition analysis suggested that the mitochondrial sequences were biased toward A and T, with A + T content ranged from 57.40% for H. anisitsi to 60.38% for H. ocellifer. The Bayesian analysis based on sequences of 35 different mitogenomes did not fully support the arrangement of genera within Characidae family. These results might indicate some problems with the current taxonomic system of Characidae, and contribute to further studies on the Characidae phylogeny.