Phylogenetics of the crayfish subgenus Crockerinus, genus Orconectes (Decapoda: Cambaridae), based on Cytochrome Oxidase I

The crayfish family Cambaridae is a diverse and important component of North American aquatic diversity. Although the family has enjoyed a relatively high level of taxonomic stability, few phylogenetic hypotheses of relationships within the family using empirical data analyses exist. We present here a phylogenetic analysis of the subgenus Crockerinus, genus Orconectes, using nucleotide sequence data from the mitochondrial gene region Cytochrome Oxidase I (COI). Using both parsimony and likelihood analyses, our results do not support the monophyly of the subgenus Crockerinus and show only partial support for the use of pleopod morphology for classification. For the species examined in this study, COI exhibited a relatively high rate of substitution, especially at the third codon position. This demonstrates the potential use of COI for inferring interspecitic relationships among cambarid crayfishes.