Caridina venusta, 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 : 52

Caridina venusta sp. nov.

( Figs. 3–4 )

Material examined: Holotype: male (06-1-3), Total length 18 mm. Paratypes: 4 male and 6 female, Total length 15–24 mm. Type locality: Specimens were collected in Yingde County, Guangdon Province (N23°54.3´, E113°15.8´) on July 17, 2006.

Habitat: They inhabit a stream with sandy bottom and big stones with few aquatic macrophytes in a mountain gully.

Description: Rostrum short, only reaching to mid or often to end of eyes, occasionally extending to near distal end of 1st segment of antennular peduncle. No teeth on rostrum. Pterygostomian angle rounded, without spine. Telson with 1 short cone-shaped posteromedian projection, 6 pairs of dorso-lateral spines, 4 pairs of plume-seta on distal margin which were similar in size, length and thickness. Stylocerite longer, slightly beyond 1st segment of antennular peduncle; ultimate segment shorter than 2nd segment, total length of two terminal segments nearly equal to length of 1st segment. Scaphocerite 2.7–2.9 times as long as wide. Outerdistal angle of 1st maxilliped endopod ending broadly triangular. Half of 3rd maxilliped ultimate segment reaching beyond end of antennular peduncle; ultimate segment longer than penultimate segment, but shorter than antepenultimate segment, ending in a single terminal claw with bearing 8–9 short thorns on ventral margin. First pereiopod stout, nearly reaching to mid of 3rd segment of antennular peduncle; carpus deeply concaved in distal margin, about 1.7 times as long as wide; chela 2 times as long as wide, dactylus approximately equal to or shorter than palm. Second pereiopod slender, reaching beyond distal end of antennular peduncle; carpus slightly sunk in distal margin and 6.2 times as long as wide, chela 3 times long as wide, dactylus nearly 1.4 times as long as palm. 1/3 length of 3rd pereiopod propodus exceeding to end of antennular peduncle; carpus 0.79 times as long as propodus, propodus 3.2 times as long as dactylus, dactylus 3.6–3.8 times as long as wide, with 6–7 accessory spines along flexor margin. Fifth pereiopod approximately reaching to mid of 3rd segment of antennular peduncle; carpus 0.6 times as long as propodus, propodus 3.3 times as long as dactylus, dactylus 5.1 times as long as broad, and with 71–74 comb-like spinules along flexor margin. Endopod of male 1st pleopod long and narrow, tongue-like slide, distally acuted, 2.6 times as long as wide, slender seta armed both exterior and anterior margin; appendix interna on distal 1/3, reaching slightly beyond distal margin of endopod. Appendix masculine of male 2nd pleopod tapering, armed on inner edge and distal end with long and thin movable spines; appendix interna stout, with hooks on inner terminal angle, nearly reaching mid of appendix masculine. Uropodal diaeresis with 21–24 movable denticles.

Body of live specimens alternately covered with red-brown and white stripes. Rostrum, 2/3 regions of the back cephalothorax, 3rd abdomen segment, the front half part of 4th abdomen segment and telson, middle of uropods appeared red-brown, other parts are white. The stripe in connecting areas of cephalothorax serrated. The red-brown stripe shape on 3rd to 4th abdomen segments appeared inverse trapezoid. Most significantly, there is a brown spot on the cephalothorax just under behind the orbit.

Discussion: The new species much resembles Caridina huananensis ( Liang, 2004) in the characteristics of short rostrum, absence of rostral teeth, the proportions of various joints of 1st pereiopod, the narrow dactylus of 5th pereiopod and the number of movable denticles on uropodal diaeresis. However, there are obvious differences between the two species. The new species has the longer stylocerite, beyond the distal part of 1st segment of the antennular peduncle. The carpus of 2nd pereiopod of new species is distinctly longer than the merus while carpus of 2nd pereiopod of Caridina huananensis Liang, 2004 is shorter than or equal to the merus. The dactylus of 3rd pereiopod is narrower, the length of propodus is approximately 3.7 times as long as that of the dactylus but in Caridina huananensis Liang, 2004 only 3.2 times. The endopod of 1st male pleopod is taper, shorter and wider. The appendix masculine is narrow, the bearing spines are slender and longer.

Etymology: From the Latin word venusta , for elegant, in allusion to its beautiful color of the body.

Figures

FIGURE 3. Caridina venusta 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, c, d = 0.5 mm; b, e, j, l, m, n = 0.1 mm; f, g, h, i, k = 0.2 mm.