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A new genus and new species of blind freshwater cave crab are described from Chongzuo City, Guangxi Zhuang Autonomous Region, China based on morphology and mitochondrial 16S rDNA sequences. The new genus, Phasmon gen. nov., is established for P. typhlops sp. nov., which is only the second blind cave crab known from China and East Asia. The combination of a very wide carapace, overall depigmentation, reduced orbits and vestigial unpigmented eyes of Phasmon immediately separates it from all known potamid genera. Molecular divergence estimates based on 16S rDNA suggest that the lineage to which the new genus belongs diverged from other potamids at the beginning of the Late Miocene (10.8 million years ago), much earlier than other Chinese cave crabs.

Four species of freshwater crabs from three genera and two families (Cantopotamon hengqinense Huang, Ahyong & Shih, 2017, Nanhaipotamon guangdongense Dai, 1997, Nanhaipotamon macau sp. n., and Somanniathelphusa zanklon Ng & Dudgeon, 1992) are documented from Macau for the first time. One new species, Nanhaipotamon macau sp. n., is described. The large flap on the male first gonopod terminal segment sets it apart from all other known congeners except N. wupingense Cheng, Yang, Zhong & Li, 2003, from Fujian. Characters of the carapace, male first gonopod and size, however, clearly differentiate these two species. Preliminary genetic studies also suggest that the two are not closely related. A neotype is designated for N. wupingense. The taxonomic status of Nanhaipotamon guangdongense is also discussed. Notes on the general biology and conservation status of these crabs are also included.

A new genus and species of freshwater crab, Yuebeipotamon calciatile gen. n., sp. n., is described from southern China. While the carapace features are superficially similar to species of Sinopotamon Bott, 1967, Longpotamon Shih, Huang & Ng, 2016, and Tenuilapotamon Dai, Song, Li, Chen, Wang & Hu, 1984, the new genus possesses a distinctive combination of carapace, ambulatory leg, male thoracic sternal, male abdominal, and gonopodal characters that distinguish it from these and other genera. Molecular evidence derived from the mitochondrial 16S rDNA supports the establishment of a new genus.

Caridinastellata sp. nov. is described from streams in Guangxi, south-western China. The new species clearly belongs to " Caridinaserrata group" of the genus and shows a morphological similarity with C.cantonensis Yu, 1938, C.serrata Stimpson, 1860 and C.pacbo Do et al. 2020. Caridinastellata is distinguished from congeners, based on differences in its male first pleopod and appendix masculina morphology, along with COI and 16S rRNA molecular evidence. The first pleopod endopod in male is rectangle, about 0.70 × length of exopod, about 3.7-3.9 × as long as proximally wide, inner margin concave, bearing nearly equal spine setae, outer margin bearing nearly equal long and dense spine setae; appendix interna well developed, arising from distal 1/5 of endopod, reaching to end of endopod, with cincinuli distally. The new species displays a unique and brightly coloured pattern and, therefore, can be easily recognised in the field. Liang & Zhou, 1993 described C.cavernicola from the Lenggu Cave, Du'an County, Guangxi. However, the description was based exclusively on two females. We have collected specimens of both sexes near the type locality and describe herein the previously unknown male and present morphological data on females. Data on the habitat, ecology and levels of threat of the two species are provided and suggest that they should be categorised as vulnerable (VU) under the current IUCN Criteria., (Guo-Cai Guo, Qing-Hua Chen, Wen-Jian Chen, Chao-Huang Cai, Zhao-Liang Guo.)