Caridina guilin, Cai & Ng, 2018

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), Zoological Studies 57 (27), pp. 1-33 : 19-22

publication ID	https://doi.org/ 10.6620/ZS.2018.57-27
DOI	https://doi.org/10.5281/zenodo.12826770
persistent identifier	https://treatment.plazi.org/id/03998788-FF8E-0405-C9E7-FF163DE0F842
treatment provided by	Felipe
scientific name	Caridina guilin
status	sp. nov.

Treatment

Caridina guilin View in CoL sp. nov.

( Figs. 14 View Fig , 15 View Fig )

urn:lsid:zoobank.org:act:8126B546-4886-46AC-96F7-FDCCA77549F0

Material examined: Holotype: female, cl 6.5 mm, IZCAS DE 5039 View Materials , 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 View Fig View Fig View Fig View Fig View Fig ) 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 View Fig ) 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 View Fig ) with prominent posteromedian projection, posterior margin acutely triangular, lateral pair of spines subequal to intermedian pairs.

Eyes well developed ( Figs. 14A View Fig , 15A View Fig ). 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 View Fig ) 3.2 times as long as wide, outer margin straight.

Mouthparts as figured. Mandible ( Fig. 14C View Fig ) with blunt teeth at extremity of incisor process. Maxillula ( Fig. 14D View Fig ) 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 View Fig ) stout, terminating in triangular projection. Endopod of second maxilliped with fused dactylus and propodal segments. Third maxilliped ( Fig. 14F View Fig ) 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 View Fig , 15C View Fig ) 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 View Fig , 15D View Fig ) 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 View Fig , 15E, I View Fig ) 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 View Fig ) 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.

Endopod of male first pleopod ( Fig. 15E View Fig ) 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 View Fig ) reaching half endopod length; slightly longer than appendix interna.

Uropodal diaeresis ( Fig. 15H View Fig ) 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 View Fig , 15A View Fig ) (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 View Fig , 15C View Fig ) (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 View Fig ) (vs. 66-69; cf. Liang and Zhou, 1993: fig. 2(7)).

The adaptive significance of the unusual telson shape ( Fig. 14B View Fig ) 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.