 |
| Caridina sinanensis Xu, Li, Zheng & Guo, 2020 |
Abstract
From a biodiversity survey of a subterranean habitat near Sinan County, Guizhou Province, southwestern China, a new atyid shrimp of the genus Caridina H. Milne Edwards, 1837, C. sinanensis sp. nov. was discovered. The new species can be separated from other congeners based on a combination of characters including depigmentation in body and reduction of eyes, small pigment spot at the centre of the cornea, the shape of rostrum and the endopod of the 1st male pleopod, and the relatively longer appendix interna on the appendix masculina of the 2nd pleopod. Mitochondrial COI and 16S rRNA gene sequences also support the establishment of the new species. Information on the habitat, and the levels of threat are discussed to guide the conservation of C. sinanensis sp. nov.
Keywords: Caridina, COI and 16S rRNA, freshwater biodiversity, karst landform, southwestern China, spelaeology, taxonomy
 |
| Figure 2. Schematic diagram of the cave A plan view of the cave B left profile view of the cave C close-up view of cave entrance D the vegetation around the cave E light zone of cave F dim light zone of cave. |
 |
| Figure 5. The cave dwelling organisms, colour in life A–D Caridina sinanensis sp. nov. E a blind millipede F a camel cricket. |
Family Atyidae De Haan, 1849
Genus Caridina H. Milne Edwards, 1837
Caridina sinanensis sp. nov.
Diagnosis: Rostrum short, slightly sloping downwards, usually reaching to the end of the 2nd segment, occasionally reaching to the end of the 1st segment or the end of the 3rd segment of antennular peduncle, rostral formula 4–10+10–16/3–11. 1st pereiopod carpus 0.77–0.83× as long as chela, 1.6–1.7× as long as high; chela 1.9–2.2× as long as broad; fingers 1.2–1.3× as long as palm. 2nd pereiopod carpus 1.2–1.3× as long as chela, 4.7–6.1× as long as high; chela 2.2–2.9× as long as broad; fingers 1.6–2.3× as long as palm. 3rd pereiopod propodus 3.8–4.1× as long as dactylus, with 9–11 thin spines on the posterior and lateral margins. 5th pereiopod propodus 3.7–4.1 × as long as dactylus, with 11–13 thin spines on the posterior and lateral margins, dactylus terminating in one claw, with 38–44 spinules on flexor margin. Endopod of male 1st pleopod extending to 0.45–0.50× exopod length, distal half usually curved posteriorly in the natural, occasionally not bent backwards, wider proximally, subrectangular, 2.4–2.7× as long as wide, appendix interna well developed, arising from distal 1/3 of endopod, reaching beyond end of endopod. Appendix masculina of male 2nd pleopod rod-shaped, reaching to 0.51 length of endopod, appendix interna reaching to 0.93 length of appendix masculina. Uropodal diaeresis with 10–12 movable spinules. Eggs size (without eyespots) 0.67–0.82 × 1.29–1.38 mm, eggs size (containing embryos with eyes) 0.98–1.02 × 1.16–1.47 mm.
Etymology: Caridina sinanensis is named after Sinan County, where the type locality is located.
Da-Jian Xu, Deng-Xu Li, Xiao-Zhuang Zheng and Zhao-Liang Guo. 2020. Caridina sinanensis, A New Species of Stygobiotic Atyid Shrimp (Decapoda, Caridea, Atyidae) from A Karst Cave in the Guizhou Province, southwestern China. ZooKeys. 1008: 17-35. DOI: 10.3897/zookeys.1008.54190
