Study On The Molecular Phylogeny Of The Family Diogenidae Ortmann,1892 (Decapoda:Anomura:Paguroidea)

Diogenidae Ortmann,1892 is the second-largest family of Paguroidea,Anomura.Clibanarius Dana,1852 is one of the most diverse genera within Diogenidae.However,there are very limited studies on the phylogeny of Clibanarius.In this study,we reconstruct the molecular phylogeny of Clibanarius based on two mitochondrial(16S rRNA and COI)and two nuclear protein-coding(NaK and PEPCK)genes using a multigene phylogenetic approach.A total of 11 selected Clibanarius species from the Indo-West Pacific are analyzed,and the Bayesian and maximum likelihood analyses produced identical results in topology.The current research suggests that C.rutilus and C.infraspinatus are more closely related to each other than to C.snelliusi,and C.striolatus shows a close relationship to C.longitarsus.The close association of C.merguiensis with C.englaucus and C.humilis is strongly supported with C.virescens being divergent from them.Our phylogenetic results contradict the morphologieal classification scheme proposed for Clibanarius and indicate that the relative length of dactyls and propodi is not phylogenetically significant in Clibanarius.In addition,we speculate that the morphological characteristic of the median cleft of the telson may be phylogenetically important for Clibanarius.The phylogenetic relationships of Diogenidae have been poorly documented in the previous studies.Here,we reconstruct the phylogeny and analyze divergence times of this family based on two mitochondrial(16S rRNA and COI)and two nuclear protein-coding(NaK and PEPCK)genes for 14 genera of Diogenidae including 52 species.It is suggested that the studied 52 Diogenid species can be divided into three clades.The genera Clibanarius,Calcinus,Dardanus,Paguropsina and Diogenes show to be monophyletic.However,Paguristes and Areopaguristes are recovered as polyphyletic,with Diogenidae paraphyletic.The taxonomic status of genera Paguristes and Areopaguristes is obscure,which requires further revision according to morphological characteristics.In addition,divergence time analysis dates the origin of Diogenidae to the Middle Jurassic(c.169.59 Mya,95%HPD:189.29-148.13 Mya)and shows that species of Diogenidae may radiate from shallow water to deep sea during the Early Cretaceous(c.142.02 Mya,95%HPD:164.45-121.78 Mya).However,some Diogenid species still remain in the shallow water.The present molecular phylogeny indicates that Diogenid hermit crabs have a history of multiple invasions into the deep sea.In this study,the mitochondrial and nuclear protein-coding gene concatenated dataset are used to explore the interspecific relationships of Clibanarius for the first time.The most comprehensive molecular phylogenetic analysis of Diogenidae are provided,adding molecular evidences for taxonomy and phylogeny of this family.Meanwhile,this study also provides fundamental information for the systematic evolution of Anomura.