LAUSR

The sequences of mitochondrial cytochrome c oxidase subunit I (CO1) genes of eight species crabs of Grapsoidea were determined and analyzed in this paper. The traditional classification is that Grapsidae contains four subfamilies comprising Grapsinae, Varuninae, Sesarminae, and Plagusiinae, which are also treated as families in some studies. There is a lack of clarity in the classification of some species, such as Eriocheir species. In this study, we conducted the first exploration of evolutionary relationships among species based on analysis of the molecular data of CO1 genes of eight species (Sesarmops sinensis, Clistocoeloma sinensis, Perisesarma bidens, Helice latimera, Helice tientsinensis, Helice wuana, Hemigrapsus sanguineus, and Varuna litterata). We provide a detailed and comprehensive view of the phylogenetic relationships of the Grapsoidea species determined by maximum likelihood and Bayesian inference analyses. The results show that S. sinensis, C. sinensis, and P. bidens are part of Sesarmidae, Grapsoidea, while H. latimera, H. tientsinensis, H. wuana, H. sanguineus, and V. litterata belong to Varunidae, Grapsoidea. The results revealed that Varunidae should be monophyletic and Sesarmidae should be paraphyletic.