Caridina stellata, a new species of atyid shrimp (Decapoda, Caridea, Atyidae) with the male description of Caridina cavernicola Liang & Zhou, 1993 from Guangxi, China

Caridina stellata sp. nov. is described from streams in Guangxi, south-western China. The new species clearly belongs to "Caridina serrata 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. Caridina stellata 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