Caridina meridionalis, Wang, Liqing, Liang, Xiangqiu & Li, Fan, 2008

Wang, Liqing, Liang, Xiangqiu & Li, Fan, 2008, Descriptions of four new species of Caridina (Decapoda: Atyidae) from China, Zootaxa 1726, pp. 49-59 : 56-58

Caridina meridionalis sp. nov.

( Figs.7–8 )

Material examined: Holotype: male (06-12-1), total length 17 mm. Paratypes: 2 male and 7 female, Total length 14–21 mm. Type locality: The examined species were collected in Heyuan County, Guangdong Province on July 15, 2006.

Habitat: They crawl on the roots and stems of aquatic macrophytes thickly covered on the shallow mountain gully.

Description: Rostrum short and narrow slightly inclined downwards distally, reaching to distal end of eyes or end of 1st segment of antennular peduncle. Rostal formula: 3–8+2–3/1–2 (usually with 1 tooth). Ventral teeth just located below rostral tip. Pterygostomian margin rounded and without spine. Telson with 1 developed stout cone-shaped postero-median projection, 6–7 pairs of dorso-lateral spines, 4 pairs of plumeseta on distal margin. All setae-like pairs similar in size, length and thickness, but sub-lateral pair often slightly shorter than lateral and intermediate pairs. Stylocerite short, not reaching to end of 1st segment of antennular peduncle, ultimate segment slight longer than 2nd segment, total length of two terminal segments shorter than length of 1st segment. Scaphocerite broad, 2.7 times as long as wide. Outerodistal angle of endopod of 1st maxilliped ending in broadly triangular. 1/4 length of ultimate segment of 3rd maxilliped exceeding to end of antennular peduncle, ultimate one apparently longer than penultimate but shorter than antepenultimate segment, ending in a single terminal claw and bearing 7–8 short thorns on distal ventral margin. First pereiopod short and stout, reaching slightly beyond distal end of 1st segment of antennular peduncle; carpus deeply excavated in distal margin, about 1.6 times as long as wide; chela broad and hypertrophy, 1.9 times as long as wide; dactylus 0.7 times as long as palm. Second pereiopod apparently long and stout, end of palm slightly exceeding to distal of antennular peduncle, carpus slightly excavated in distal margin and 5 times as long as wide, chela 2.8 times long as wide, dactylus 1.2 times as long as palm; 1/5 to 1/4 of 3rd pereiopod propodus exceeding to end of antennular peduncle; carpus 0.7 times as long as propodus, propodus 4.3 times as long as dactylus, dactylus short and 3 times as long as wide, with 5–6 accessory spines on flexor margin. 5th pereiopod extending to distal end of antennular peduncle; carpus 0.6 times as long as propodus, propodus 3.8 times as long as dactylus, dactylus 4.1 times as long as wide and with 53–58 comb-like spinules on ventral margin. Endopod of male 1st pleopod kidney and slide-like, broad at base and slightly narrow at end, 2.3 times long as broad, inner margin slightly sunk and bearing short spines, outer margin bearing longer seta; appendix interna on distal 1/5, more than half reaching beyond distal margin of endopod. Appendix masculine of male 2nd pleopod short stick-like, with cluster of short thrusts on inner basal edge, with two rows of movable thorns from mid to distal part of inner edge, spines on fringe and terminal parts stout and on inner slen- der; appendix interna stout, with hooks on inner angle, reaching middle of appendix masculine. Uropodal diaeresis with 18–19 movable denticles.

The cephalothorax is alternately covered with black and white stripes, and the stomach region translucent. Rostrum, the dorsal of 1st abdominal segment, 3rd to the front half part of 4th abdominal segments, 6th abdominal segment, telson and the middle of uropods appeared black. Other parts translucent.

Discussion: The characteristic short rostrum, stylocerite and dactylus of 1st pereiopod etc., of this new species resembles Caridina clinata Cai , et. al. (Cai, Nguyen & Ng, 1999) which is found in Vietnam. However, compared to C. clinata , the new species has fewer rostral teeth, with a developed stout dorso-median projection on distal end of telson, total length of 2nd and 3rd segment shorter than 1st segment of antennular peduncle, scaphocerite shorter and broader, 1st pereiopod carpus longer than merus. Third pereiopod dactylus shorter and only 1/4.3 of propodus (vs 1/ 3.6 in C. clinata ); more accessory spines on flexor margin of 5th pereiopod dactylus, the apparently shorter and broader endopod, of male 1st pleopod and the longer appendix interna.

Etymology: The species is named after its distribution area, the southern part of China.

Figures

FIGURE 7. Caridina meridionalis sp. nov. a. anterior portion of cephalothorax, lateral view; b. terminal portion of telson, dorsal view; c. 1 st antenna; d. 2 nd antenna; e. endopod of 1 st maxilliped; f. 3 rd maxilliped; g. 1 st pereiopod; h. 2 nd pereiopod; i. 3 rd pereiopod; j. dactylus of 3 rd pereiopod, enlarged; k. 5 th pereiopod; l. dactylus of 5 th pereiopod, enlarged; m. endopod of 1 st male pleopod; n. appendix masculina of 2 nd pleopod. Scale: a, f, g, h, i, k = 0.5 mm; b, c, d = 0.2 mm; e, j, 1, m, n = 0.1 mm.