Diversity of Taiwanese Brackish Crabs Genus Stimpson, 1858 (Crustacea: Brachyura: Varunidae) based on DNA Barcodes, with Descriptions of Two New Species.

Species in the brackish crab genus are common in the seashore and estuary habitats with freshwater input. Due to their similar morphologies and dull colorations, it is always difficult to distinguish the species in this genus. In this study, the DNA barcode gene (cytochrome oxidase subunit I) was used to help identify from Taiwan. The results showed that the 10 species can be identified successfully based on , with intraspecific distances below 1.54% and interspecific distances of 12.2%-19.57%. In addition, two new species of are described from Taiwan. sp. nov. from southern Taiwan is similar to (Rathbun, 1914), and sp. nov. from southern Taiwan and the southern Philippines resembles aff. (A. Milne-Edwards, 1873) and Heller, 1865. Both species can be distinguished from other congeners by a suite of characters, including the carapace, orbital region, frontal region, telson of male pleon, male first gonopod, and setae on ambulatory legs.