Caridina alu, 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 : 5-9

publication ID	https://doi.org/ 10.6620/ZS.2018.57-27
DOI	https://doi.org/10.5281/zenodo.12826762
persistent identifier	https://treatment.plazi.org/id/03998788-FF98-0418-CB53-FBD73FFEFA42
treatment provided by	Felipe
scientific name	Caridina alu
status	sp. nov.

Treatment

Caridina alu View in CoL sp. nov.

( Figs. 4-6 View Fig View Fig View Fig )

urn:lsid:zoobank.org:act:F7760EDF-36A2-48DD-9B49-409B6B51A1CD

Material examined: Holotype: male, cl 6.5 mm, IZCAS DE 5029 View Materials , caught by fish traps in subterranean river, Alu Cave , behind a hotel at Alufa Village , Luxi County, Yunnan Province, southern China, coll. Kos, B. Sket & Velkovrh. 24 Nov 1995 . Paratypes: 1 female, cl 4.0 mm, IZCAS DE 5030, same data as holotype; 1 male, cl 6.0 mm, 1 female, cl 4.8 mm, RMNH.CRUS. D.57290; 1 male, cl 6.2 mm, 1 female, cl 5.6 mm, UL, same data as holotype; 2 males, cl 5.8-6.3 mm, 4 females, 3.0- 4.7 mm, cl 4.2-6.2 mm, ZRC 2018.0481, same data as holotype.

Comparative material examined: Caridina sphyrapoda Liang and Zhou, 1993 - holotype: male, cl 5.5 mm, SFU 85a-8-1, Longdong river, Laibing County, Guangxi Province, China, coll. J. Zhou, 24 May 1985. Paratype: 1 female, cl 3.8 mm, 1 ovigerous female, cl 5.8 mm, SFU 85a-8-2, same data as holotype. Others: 3 males, cl 4.5-6.3 mm, 6 females, cl 4.7-6.6 mm, IZCAS, stream near Kuiyang Town, Yinlin County, Guangxi Province, coll. Y. Cai, H. Tang and H. Zhen, Nov 1993.

Description: Rostrum long ( Fig. 4A, B View Fig ), straight, reaching slightly beyond distal end of scaphocerite, armed dorsally with 16-24 teeth, of which 5-8 are situated on carapace behind posterior margin of orbital margin, occupying about half carapace length, armed ventrally with 4-12 (mode 7-10) teeth. Orbit narrow; antennal spine sharp, completely fused with suborbital angle. Pterygostomian angle broadly rounded.

Sixth abdominal somite twice as long as fifth abdominal somite, about half carapace length, slightly shorter than telson. Telson ( Fig. 5G View Fig ) without posteromedian projection, posterior margin rounded, lateral pair of spines longer than sub-lateral pairs, subequal to intermediate pairs of spines.

Eyes degenerated ( Fig. 4A, B View Fig ), small, pigment at centre of cornea. Antennular peduncle ( Fig. 5A View Fig ) 0.54 times as long as carapace. Antennular flagellum extraordinary long, more than twice total length. Stylocerite reaching 0.74 basal segment length of antennular peduncle or to end of segment. Scaphocerite ( Fig. 5B View Fig ) 3 times as long as wide, outer margin slightly concave.

Mouthparts as figured. Mandible ( Fig. 4C View Fig ) with blunt teeth at extremity of incisor process. Maxillula ( Fig. 4D View Fig ) with simple palp, lower lacinia broadly rounded, upper lacinia broadly elongated, inner edge straight, with dense setae and teeth. Maxilla ( Fig. 4E View Fig ) with slender palp, upper endite subdivided, scaphognathite tapering with numerous long hooked setae posteriorly. Palp of first maxilliped stout ( Fig. 4F View Fig ), terminating in projection. Endopod of second maxilliped ( Fig. 5C View Fig ) with fused dactylus and propodal segments. Third maxilliped ( Fig. 5D View Fig ) reaching to distal end of antennular peduncle, ending in single terminal claw; exopod reaching posterior 0.25 penultimate segment length, ultimate segment shorter than penultimate segment. Epipods on first 4 pereiopods.

First pereiopod ( Fig. 5E View Fig ) short, stout, reaching slightly beyond end of basal segment of antennular peduncle, merus 2.5 times as long as broad; carpus strong concave anteriorly, 1.3 times as long as high, chela 1.7 times as long as broad, fingers slightly longer than palm. Second pereiopod ( Fig. 5F View Fig ) reaching to end of antennular peduncle, carpus 2.6 times as long as high, chela slightly shorter than carpus, 2.6 times as long as broad, fingers 1.5 times as long as palm. Third pereiopod ( Fig. 6A, B View Fig ) long, reaching slightly beyond distal end of scaphocerite, propodus 10 times as long as broad, 4.3 times as long as dactylus (claw included); dactylus ending in 2 claws, with 2-4 accessory spines on flexor margin. Fifth pereiopod ( Fig. 6C, D View Fig ) reaching distal end of scaphocerite, propodus 13 times as long as wide, 4.9 times as long as dactylus; dactylus with 25 spinules on flexor margin.

Endopod of male first pleopod ( Fig. 6E, G View Fig ) short, reaching to 0.67 endopod length, subrectangular, 3.3 times as long as wide, appendix interna situated at posterior 0.25 endopod length, extending to end of endopod. Appendix masculina of male second pleopod ( Fig. 6F, H View Fig ) slightly curved outwards, reaching 0.75 endopod length; appendix interna of male second pleopod elongated, reaching to middle of appendix masculina.

Uropodal diaeresis ( Fig. 6H View Fig ) with 9-11 spinules.

Habitat: Subterranean river in a karst cave.

Etymology: The species is named after the type locality, Alu Cave. The name is used as a noun in apposition.

Remarks: Caridina alu sp. nov. resembles Caridina sphyropoda Liang and Zhou, 1993 , from Guangxi Province in the form of its rostrum, but can be differentiated by the arrangement of its teeth: in C. alu , the postorbital teeth are widely placed, occupying half the length of the carapace ( Fig. 4A, B View Fig ) (vs. postorbital teeth are closely placed, occupying only a third of the carapace length; cf. Liang and Zhou, 1993: fig. 4(1)); the eyes are degenerated ( Fig. 4A, B View Fig ) (vs. developed; cf. Liang and Zhou, 1993: fig. 4(1)); the endopod is rectangular ( Fig. 6G View Fig ) (vs. sigmoid; cf. Liang and Zhou, 1993: fig. 4(8)), and the telson does not possess a posteromedian projection ( Fig. 5G View Fig ) (vs. projection distinctly present; cf. Liang and Zhou, 1993: fig. 4(2)).