Taxonomic status and phylogenetic relationship of Anomura (Crustacea: Decapoda) based on mitochondrial sequences and gene order rearrangements.

The complete mitochondrial genome (mitogenome) contributed crucial information, which could improve the better understanding of molecular phylogenetic analysis, evolution, and gene rearrangements. However, only a few Coenobitidae and Albuneidae mitogenomes have been described, and controversies about the Anomuran phylogeny remain. Here, we determined three Coenobitidae species (Coenobita perlatus, Coenobita rugosus, Coenobita clypeatus) and one Albuneidae species (Emerita talpoida). As the representative species of genera or families, and even the first species of the genus, supplementing these four species is essential to study the phylogenetic relationships within Anomura. Most of the four novel mitogenomes have the typical 37 genes, except for E. talpoida, which lacked trnF. Through combining these new data with 31 Anomuran mitogenomes from Genbank, different gene rearrangement patterns and internal phylogenetic relationships of Anomura were investigated. In our phylogeny analysis, all the Anomuran species were clustered into one group, and the polyphyly of Paguroidea was well supported. Moreover, various peculiar mitochondrial gene orders (MGOs) were summarized among Anomura and preliminary determined their rearrangement mechanisms through CREx. Twenty different MGOs were suggested in our research, and we were focused seven MGO patterns (Pattern A-J) in the process of discussing the gene rearrangement mechanism. Currently making full use of the large taxon sampling, our results provide valuable information on the evolutionary status of Anomuran species and are available for systematic rearrangement and phylogenetic analyses.