Molecular phylogeny of the superfamily Palaemonoidea (Crustacea : Decapoda : Caridea) based on mitochondrial and nuclear DNA reveals discrepancies with the current classification

Abstract

Palaemonoidea is one of the most speciose superfamilies of Caridea. Since it was established, several classification schemes of Palaemonoidea have been proposed and modified. However, the current classification of Palaemonoidea is still in dispute. In this study, one mitochondrial gene (16S rRNA) and three nuclear genes (histone 3, 18S rRNA and 28S rRNA) were used to explore the phylogenetic relationships among the subgroups of the superfamily Palaemonoidea, including seven families with 25 affiliated genera. Based on the combined data with both maximum likelihood and Bayesian inference analyses, the results support the monophyly of Anchistioididae and Hymenoceridae. In contrast, Gnathophyllidae is suggested to be paraphyletic and Palaemonidae is shown to be a polyphyletic group. Our analyses reveal that the subfamily Palaemoninae could be approximately divided into three clades, and the branchiostegal groove is the probable morphological evidence of the environmental transition from sea to fresh water. Besides, for some of the Palaemonoidea families, their taxonomic status is obscure. A revision of Palaemonoidea and a re-evaluation of its constituent taxa appear to be necessary even though the systematic status of the subfamily Pontoniinae is still undetermined.