Caridina guilin Cai & Ng, 2018, sp. nov.
Creators: name: Cai, Yixiong
name: Ng, Peter Kee Lin
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Atyidae
Caridina
Caridina guilin

description: Caridina guilin sp. nov.   
(Figs. 14, 15)  
urn:lsid:zoobank.org:act: 8126B546-4886-46AC-96F7- FDCCA77549F0  
 Material examined: Holotype: female, cl 6.5 mm, IZCAS DE 5039, karst cave near Guilin city, Guangxi Province, southern China, coll. B. Sket, 1 Dec 1977. Paratype: 1 male, cl 4.3 mm, ZRC 2018.0485, same data as holotype.   
 Comparative material examined: Caridina cavernicola Liang and Zhou, 1993 - Holotype: female, cl 7.3 mm, SFU 82A-15-1, Lenggu Cave, Du’an County, coll. 22 May 1982. Paratype: 1 female, cl 7.0 mm, SFU, 82A-15-2, same data as holotype.   
 Description: Rostrum (Figs. 14A, 15A) straight, reaching to or beyond distal end of scaphocerite, rostral formula 6-8 + 20-22/7- 12. Antennal spine fused with suborbital angle. Pterygostomian angle broadly rounded.   
Telson sexually dimorphic. Telson in male (Fig. 14B) with prominent posteromedian projection, posterior margin rounded, lateral pair of spines longer than intermediate pairs, sub-lateral pairs being shortest; telson in female (Fig. 15B) with prominent posteromedian projection, posterior margin acutely triangular, lateral pair of spines subequal to intermedian pairs.  
Eyes well developed (Figs. 14A, 15A). Antennular peduncle about 0.6 times carapace length. Stylocerite reaching to 0.8 length or to end of basal segment of antennular peduncle. Scaphocerite (Fig. 14M) 3.2 times as long as wide, outer margin straight.  
Mouthparts as figured. Mandible (Fig. 14C) with blunt teeth at extremity of incisor process. Maxillula (Fig. 14D) with simple palp, lower lacinia broadly rounded, upper lacinia broadly elongated, inner edge straight. Maxilla with slender palp, upper endite subdivided, scaphognathite tapering with numerous long setae posteriorly. Palp of first maxilliped (Fig. 14E) stout, terminating in triangular projection. Endopod of second maxilliped with fused dactylus and propodal segments. Third maxilliped (Fig. 14F) reaching to distal end of antennular peduncle, ending in single terminal claw; exopod reaching posterior quarter of penultimate segment length, ultimate segment distinctly shorter than pentultimate segment. Epipods on first 4 pereiopods.  
First pereiopod (Figs. 14G, 15C) short, stout, reaching end of basal segment of antennular peduncle, merus 1.5 times in female and 2.0 times in male as long as broad; carpus strongly concave anteriorly, as long as high, chela 2.0 times as long as broad, fingers 0.6 times as long as palm. Second pereiopod (Figs. 14H, 15D) reaching end of second segment of antennular peduncle, carpus 3.0 times as long as high, chela slightly longer than carpus, 2.1-2.4 times as long as broad, fingers 0.7 times as long as palm. Third pereiopod (Figs. 14I, J, 15E, I) reaching slightly beyond distal end of second segment of antennular peduncle, propodus 10 times as long as broad, 4.5 times as long as dactylus (including claw); dactylus with terminal claw, with 5 spines. Fifth pereiopod (Fig. 14K, J) reaching to end of basal segment of antennular peduncle, propodus 14 times as long as wide, 5.8 times as long as dactylus; dactylus with 56 spinules on flexor margin.  
© 2018 Academia Sinica, Taiwan  
© 2018 Academia Sinica, Taiwan  
© 2018 Academia Sinica, Taiwan  
Endopod of male first pleopod (Fig. 15E) short, reaching to 0.2 endopod length, sub-triangular, 1.7 times as long as wide, appendix interna at distal end of endopod, reaching remarkably beyond distal end of endopod. Appendix masculina of male second pleopod (Fig. 15G) reaching half endopod length; slightly longer than appendix interna.  
Uropodal diaeresis (Fig. 15H) with 9 or 10 spinules.  
 Habitat: Stream in a karst cave.   
 Etymology: Caridina guilin sp. nov. is named after the type locality, Guilin city in Guangxi Province. The name is used as a noun in apposition.   
 Remarks: Caridina guilin sp. nov. bears a close resemblance to C. cavernicola Liang and Zhou, 1993 (described from Du’an County of Guangxi Province), in the long rostrum and the form of telson in female, which terminates in an acute triangle. The latter character is unusual and has so far not been reported in any other congener. However, the new species can easily be distinguished from C. cavernicola by the smaller number of ventral teeth on the rostrum (7-12, Figs. 14A, 15A) (vs. 20-24; cf. Liang and Zhou, 1993: fig. 2(1)); the shorter carpus of the first pereiopod which is as long as high (Figs. 14G, 15C) (vs. 1.4- 1.7 and as long as high; cf. Liang and Zhou, 1993: fig. 2(4)); and the smaller number of spines (56) on the dactylus of the fifth pereiopod (Fig. 14J) (vs. 66-69; cf. Liang and Zhou, 1993: fig. 2(7)).   
 The adaptive significance of the unusual telson shape (Fig. 14B) is unknown, but may suggest that C. guilin and C. cavernicola are related, although they occur in two separate cave systems some distance from each other.   
 Distribution: Guangxi Province (Guilin), China.
description: Published as part of Cai, Yixiong & Ng, Peter Kee Lin, 2018, Freshwater Shrimps from Karst Caves of Southern China, with Descriptions of Seven New Species and the Identity of Typhlocaridina linyunensis Li and Luo, 2001 (Crustacea: Decapoda: Caridea), pp. 1-33 in Zoological Studies 57 (27) on pages 19-22, DOI: 10.6620/ZS.2018.57-27, http://zenodo.org/record/13314991