Caridina tumida, 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 : 54-56

Caridina tumida sp. nov.

( Figs. 5–6 )

Material examined: Holotype: male (06-2-1), Total length 18 mm. Paratypes: 1 male and 6 female, total length 14–19 mm, two female with eggs which measured 0.57–0.63 × 0.99–1.02 mm in diameter. Type locality: The examined specimens were collected in Yingde County, Guangdong Province (N 23°54.4´, E113°15.1´) on July 15, 2006.

Habitat: They crawl on the deadwood and defoliate leaves in the upstream of rivers with few aquatic macrophyte of the mountain waterfall.

Description: Rostrum short and horizontal, nearly reaching to middle of eyes or end of 1st segment of antennular peduncle; rostral formula: 0/0–2 (usually with 1 tooth), ventral teeth located on distal end, just below rostral tip. Pterygostomial angle rounded, without spine. Telson with one short cone-shaped posteromedian projection, 6–7 pairs of dorso-lateral spines, 3–4 pairs of plume-seta on distal margin which are similar in size, length and thickness, but sub-lateral pair often slightly shorter than lateral and intermediate pairs. Stylocerite long, reaching beyond end of 1st segment, ultimate segment slightly shorter than 2nd segment, total length of two terminal segments approximately equal to length of 1st segment. Scaphocerite broad, 2.7 times as long as wide. Outerodistal angle of endopod of 1st maxilliped ending in broadly triangular. Ultimate segment of 3rd maxilliped reaching beyond end of antennular peduncle, and apparently longer than penultimate and shorter than antepenultimate segment, ending in a single terminal claw and bearing 6–7 short thorns on distal ventral margin. First pereiopod stout, nearly reaching to end of 1st segment of antennular peduncle; carpus deeply excavated in distal margin, about 1.4 times as long as wide; chela apparently broad and hypertrophy, 1.8 times as long as wide, dactylus shorter than palm, 0.7 times as palm. Second pereiopod long and strong, slightly exceeding to distal end of antennular peduncle; carpus slightly sunk in distal margin, 4.9 times as long as wide; chela 2.4 times as long as wide, dactylus nearly 1.4 times as long as palm. Distal end of dactylus of 3rd pereiopod reaching to end of antennular peduncle; carpus 0.7 times as long as propodus, propodus 3.5 times as long as dactylus, dactylus 3.3 times as long as wide, with 6 accessory spines along flexor margin. Fifth pereiopod reaching to end of eyes, carpus 0.6 times as long as propodus, propodus 3.3 times as long as dactylus, dactylus 3.9 times as long as broad, and with 55 comb-like spinules on flexor margin. Endopod of male 1st pleopod long and narrow, leaf-like slide, interior margin slightly concaved, 2.8 times as long as broad, long and simple seta armed both exterior and anterior margin; appendix interna on distal 1/3, reaching slightly beyond distal end of endopod. Appendix masculine of male 2nd pleopod short and stick-like, with cluster of short thorns on inner base, with two rows of movable spines on inner edge to distal margin, spines on fringe larger and slender on inner, stronger on distal end; appendix interna stout, with hooks on inner terminal angle, not reaching middle of appendix masculine. Uropodal diaeresis with 21–23 movable denticles. The body of live specimens is reddish. The pigments on cephalothorax, 3rd and 6th abdomen segments are dense, but sporadic on other parts.

Discussion: Caridina tumida is similar with C. spinosipes (Liang, Guo & Tang, 1999) in the characteristics of short rostrum, ventral tooth located rostral tip, the distinctly broad and expanse chela of 1st pereiopod, the short and broad carpus and the dactylus shorter than palm. However, it differs from C. spinosipes in that it has a longer stylocerite protruding 1st of antennual peduncle, longer carpus than merus of 1st pereiopod, shorter and broader endopod of male 1st pleopod with slight leaf-like shape, different shape and structure of appendix masculine of male 2nd pleopod and the more number of movable denticles armed on uropodal diaeresis.

Etymology: From the Latin word tumida , for swollen, referring to the form of the chela of the first pereiopod.

Figures

FIGURE 5. Caridina tumida 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, 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, f, g, h, i, k = 0.5 mm; b, e, j, l = 0.1 mm; m, n = 0.2 mm.