On a new species of Chinapotamon Dai & Naiyanetr, 1994 and the first record of Chinapotamon pusillum (Song, 1984) and Songpotamon malipoense Shi, Pan & Sun, 2023 (Crustacea, Decapoda, Brachyura, Potamidae) from northern Vietnam

The presence of freshwater crabs of the genus Chinapotamon Dai & Naiyanetr, 1994 (Potamidae) in northern Vietnam was only recently established with the description of C. cf. depressum (Dai, Song, Li & Liang, 1980) from Cao Bang Province, and C. cf. pusillum (Song, 1984) and C. insulare Le, Dang & Do, 2024, from Quang Ninh Province (Le et al. 2024). Re-examination of the specimens referring to the first two species specimens in comparison with the holotypes and original descriptions of C. depressum and C. pusillum , revealed that C. cf. depressum represents a new species, herein named C. halangense sp. nov. While C. cf. pusillum is confirmed to be C. pusillum , a recorda that represents a range extension for the latter species. Chinapotamon halangense sp. nov. , can be distinguished from congeners by distinct carapace proportions and clear differences in male gonopod morphology. In addition, we report on the discovery of Songpotamon malipoense Shi, Pan & Sun, 2023, from Ha Giang Province in northern Vietnam. As a result of these recent discoveries, Vietnam’s freshwater crab fauna now comprises 65 recognized species.