Chapter 17 - The Phylogenetic Utility of the Mitochondrial Cytochrome b Gene for Inferring Relationships among Actinopterygian Fishes

Abstract

The objective of this chapter is to test the phylogenetic utility of the mitochondrial cytochrome b gene by analyzing the relationships of monophyletic Actinopterygii or ray-finned fishes at different hierarchic levels. Modern actinopterygians are the most diverse of all vertebrate groups and include more than 25,000 species. In order to assess the utility of the cytochrome b gene, actinopterygian fishes representing a diverse array of taxa and divergence times were selected. Facts and figures supporting phylogenetic hypothesis of actinopterygian fishes, including only the taxa, are examined based on morphological data from various sources. Although this chapter focuses on the cytochrome b gene, this study serves as a model for further studies that examines the utility of other genes. It lists the actinopterygian species examined in this study and their current classification. The mitochondrial cytochrome b gene sequences for the remaining 18 ray-finned fishes were retrieved from GenBank. The results of Cytochrome b sequence variation, base compositional bias, and amino acids differences are very important from the analytical point of view as is the assessment of the phylogenetic utility of the mitochondrial cytochrome b gene arrived at by examining taxonomic congruence between molecular- and morphological-based phylogenetic hypotheses.