Caridina yunnanensi

Ng, Y. Cai and P. K. L. & Ng, Cai P. K. L., 2010, revision of Caridina yunnanensis and its allied species (Crustacea: Decapoda: Caridea: Atyidae) from Yunnan, southern China, with description of one new species, Journal of Natural History 35, pp. 213-227 : 214-217

Caridina yunnanensi s Yu, 1938 (®gures 2±4) Caridina yunnanensis Yu, 1938: 304 ; ®gures 15, 16 (type locality: Xundian (Hsun-tien) County, Yunnan); Liang and Yan, 1985: 196.

Material examined

NEOTYPE:, l cl. 4.3 mm ( ZRC.1998.941), Shangyo u reservoir, Songming County, Yunnan, southern China.

Other material. Two ll, cl. 5.0± 5.1mm, one m, cl. 5.5 mm, one m (ovigerous), cl. 6.0 mm ( ZRC.1998.921); six ll, cl. 4.1±5.1 mm, two mm, cl. 5.2±6.0 mm, one m (ovigerous), cl. 6.0 mm, data same as neotype ( IZAS) .

Description

Rostrum straight or slightly curved downwards, nearly reaching to base of third segment of antennular peduncle or to end of this segment, rostral formula: 5±9 1 4±10/2±10 (3±7), more widely spaced anteriorly than posteriorly; inferior orbital angle of carapace fused with antennal spine; pterygostomial angle subrectangular.

Abdomen with sixth somite 0.4 times as long as carapace, 1.8 times as long as ®fth somite. Telson ending in median projection; ®ve pairs of dorsal spinules, one pair of dorso-lateral spines near distal end, four or nine pairs of setae on distal margin, lateral pair slightly longer than intermediate pairs; preanal carina rounded, unarmed.

Eyes well developed. Antennular peduncle stout, 0.56±0.66 times as long as carapace, basal segment slightly longer than length of peduncle, second segment longer than the third; stylocerite not reaching end of basal segment of antennular peduncle. Scaphocerite 3.4 times as long as wide. Branchial formula normal, with arthropod of second maxilliped poorly developed. Epipods present on ®rst four pereiopods.

Incisor process of mandible ending in irregular teeth, molar process truncated. Lower lacinia of maxillula broadly rounded, upper lacinia elongate, with a number of teeth on inner margin, palp slender. Upper endites of maxilla subdivided, palp short, scaphognathit e tapering posteriorly with some long, curved setae at posterior end. Palp of ®rst maxilliped broadly triangular. Second maxilliped typical of genus. Third maxilliped reaching slightly beyond end of antennular peduncle, ending in a single terminal claw, ultimate segment longer than penultimate segment.

First pereiopod reaching to end of basal segment of antennular peduncle; chela 2.0 times as long as broad, ®ngers 1.2 times as long as palm; carpus shorter than chela, 2.0 times as long as high, merus 3.6 times as long as broad, 1.3 times as long as carpus. Second pereiopod slender, reaching to end of antennular peduncle, chela 3.0±3.3 times as long as broad; ®ngers 1.3 times as long as palm; carpus 4.3±5.0 times as long as high; merus as long as carpus. Third pereiopod reaching end of antennular peduncle, dactylus terminating in two claws, six to eight accessory spines on ¯exor margin; propodus 4.0±4.5 times as long as dactylus (terminal spine included), 9±10 times as long as broad, numerous spinules on posterior margin. Fifth pereiopod reaching to end of second segment of antennular peduncle; dactylus stout, 37±43 spinules on ¯exor margin; propodus slender, 3.8±4.5 times as long as dactylus, 11±12 times as long as broad.

Endopod of male ®rst pleopod extending to 0.7 times exopod length, subelliptical, 2.8±3.0 times as long as broad, inner margin straight, outer margin slightly convex, simple setae longer on exterior margin, longest along anterior margin. Apendix interna on distal one-third, reaching beyond distal margin of endopod. Appendix masculina of male second pleopod reaching to 0.6 times endopod length, armed on inner edge with two rows of strong spines; appendix interna on basal onethird, 0.33 times as long as appendix masculina. Uropodal diaeresis with 13±14 spinules. Eggs 1.20± 1.28 Ö 0.75±0.85 mm in diameter.

Habitat Mountain stream ( Yu, 1938), reservoir (present study).

Distribution Xundian and Songming Counties, Yunnan (®gure 1).

Remarks

Yu (1938) described Caridina yunnanensi s in some detail on the basis of two male and seven female specimens from a mountain stream at Hsun-Tien (Xundian) County in Yunnan Province. According to Yu, his material was kept in the Fan Memorial Institute of Biology, the forerunner of the present-day Institute of Zoology, Academia Sinica, Beijing ( IZAS). His specimens cannot be located in the IZAS (also A. Dai, personal communication). They are also not present in the research station in Qingdao and Beijing Natural History Museum ( R. Liu, X. Li and S. L. Yang, personal communication). The type specimens of C. yunnanensi s Yu, 1938, are here regarded as lost.

Because C. yunnanensi s is the ®rst member of the species group described and its accurate identity is critical to resolving the taxonomy of the other members of the group, a neotype is critically needed. A male specimen (cl. 4.3 mm, ZRC.1998.941) collected from Shangyou Reservoir in Songming County, Yunnan, is here designated the neotype of C. yunnanensi s.

We have been unable to obtain specimens from the original type locality of C. yunnanensi s in Xundian County. The present locality in Songming County shares the same drainage as the adjacent Xundian County , and we are con®dent that the same species occurs in both areas. The neotype and other 14 specimens from the new type locality agree well with the description and ®gures of the species by Yu (1938), although the form of rostrum and male ®rst pleopod is more variable than he reported. The rostrum of the present specimens is variable in length, from reaching to the end of the second segment of the antennular peduncle (n 5 4) , to extending beyond it (n 5 4), and even to the end of the antennular peduncle itself (n 5 7). The appendix interna of the male ®rst pleopod reaches to slightly beyond the distal margin of the endopod (n 5 2) to well beyond it (n 5 4).