Freshwater Shrimps Of The Family Atyidae (Crustacea: Decapoda: Caridea) From Peninsular Malaysia And Singapore Author Cai, Yixiong Author Ng, Peter K. L. Author Choy, Satish text Raffles Bulletin of Zoology 2007 2007-08-31 55 2 277 309 journal article 10.5281/zenodo.5333541 2345-7600 5333541 Caridina propinqua De Man, 1908 ( Figs. 4–6 ) Caridina propinqua De Man, 1908 a: 227 , Pl. 19, Fig. 6 [ type locality: Dhappa, near Calcutta, India ]; Kemp, 1915: 309 ; 1918: 274 ; Bouvier, 1925: 181, Figs. 375, 381; Johnson, 1961:131, Figs. 12–15 ; 1965: 8; De Silva, 1982: 127 , Fig.5 ; Ng & Choy, 1990: 17; Wowor et al., 2004: 343 , Fig. 7J–L ; Cai & Shokita, 2006a: 249; 200b: 2150. Caridina blanco Chace, 1997:7 , Fig. 2 [ type locality: Tayabus River , Luzon Island , the Philippines ]. Caridina hainanensis Liang &Yan, 1983: 211 , Fig. 1 [ type locality: Wenchang County , Hainan Island , China ]; Liang, 2004: 302 . Material examined. – Peninsular Malaysia : 9 males , cl 2.5–3.0 mm , 2 females , cl 2.3–3.0 mm, 2 ovigerous females, cl 3.6–4.0 mm, ZRC .1979.4.17.28–40, Malaysia : Johor Bahru , non-brackish stream, low tide, flowing into Sungai Skudai at mile 2, Skudai Rd , coll. E. R . Alfred , 9 Feb.1957 ; 3 males , cl 2.8–3.0 mm, 2 females , cl 3.1 mm , 3 ovigerous females, cl 3.3–3.5 mm , ZRC 2007.0374 , mangrove creek at Tanjong Sedili , Johor , Malaysia , coll. Y. Cai & N. K. Ng , 20 Sep.1999 . Singapore : 22 males , cl 2.3–3.1 mm , 18 females , cl 2.7–3.4 mm , 11 ovigerous females, cl 3.1–3.8 mm , ZRC 2007.0375 , creek in Sungei Buloh mangroves, Singapore , coll. Y. Cai , 18 Nov.1999 ; 7 males , cl 2.0–3.0 mm, 12 females , cl 2.6–3.6 mm , 8 ovigerous females, cl 2.9–3.4 mm , ZRC 2007.0376 , Mandai Kechil mangroves, Singapore , coll. REST lab, 8 Apr.1992 ; 1 male , cl 2.8 mm , 2 females , 2.6–3.0 mm, 1 ovigerous female, cl 3.4 mm , ZRC .1979.4.17.14–19, Singapore : Mile 12, Jurong Road , peaty ditches, through coconut plantation, coll. D. S. Johnson , 16 Jan.1957 ; 1 male , cl 2.5 mm , 1 female , cl 4.0 mm, 1 juv. , ZRC 2007.0377 , Singapore : Sungai Buloh , coll. P. K. L. Ng , 23 Apr.1991 ; 5 males , cl 2.0– 2.5 mm , 6 females , cl 2.2–3.3 mm , ZRC 2007.0378 , Singapore : Sungai Buloh ; coll. P. Ng , Dec.1992 ; 2 males , cl 2.5–2.6 mm , 1 female , cl 4.2 mm , 1 ovigerous female, cl 4.0 mm, ZRC 1990.11823 – 11826 , Singapore : Sungai Seletar , coll. P. Yeoh , 23 Sep.1995 . Diagnosis . – Rostrum ( Fig. 4A, B , 5A , 6A ) straight or sloping down anteriorly, reaching near middle of second segment of antennular peduncle, to end of third segment. Rostral formula: 2–4+8–16/0–4 (mostly 3), no apical teeth. Suborbital angle acute, distinctly separated from antennal spines; pterygostomian margin rounded. Preanal carina ( Figs. 4D , 5B ) with a spine. Sixth abdominal somite 0.8 times as long as carapace, 1.9 times as long as fifth somite. Telson ( Fig. 4C ) with 3 or 4 pairs of dorsal spines and small posteromedial projection, lateral pair of spines longer than intermedial pairs. Antennular peduncle long, subequal to carapace length. Stylocerite reaching to 0.8 times length of basal segment of antennular peduncle. Scaphocerite ( Figs. 4E , 5C , 6B ) 3.5–4.0 times as long as wide. First pereiopod ( Figs. 4F , 5E , 6I ) with carpus 2.1–3.3 times as long as high, chela 2.5 times as long as broad, finger longer than palm. Second pereiopod ( Figs. 4G , 5D , 6J ) with carpus 6.3–9.6 times as long as high, chela 3.4–5.0 times as long as broad, fingers twice as long as palm. Third pereiopod ( Figs. 4H, I , 5F, G , 6K ) with propodus 3.3–3.8 times as long as dactylus, propodus not enlarged. Dactylus ending in 2 claws, with 2–5 spines on flexor margin. Fifth pereiopod ( Figs. 4J, K , 5H, I , 6L ) with propodus 2.8–3.1 times as long as dactylus; dactylus ending in a claw, with 66–74 spinules on flexor margin. Endopod of male first pleopod ( Fig. 6M ) with no appendix interna. Uropodal diaeresis ( Figs. 4L , 5J ) with 13–15 spinules. Eggs sized 0.32–0.36 × 0.20–0.22 mm . Fig. 4. Caridina propinqua :A, B, cephalothorax and cephalic appendages; C, distal portion of telson; D, pre-anal carina; E, scaphocerite; F, first pereiopod; G, second pereiopod; H, third pereiopod; I, dactylus of third pereiopod; J, fifth pereiopod; K, dactylus of fifth pereiopod; L, diaeresis Scale bars: A, B, E = 1 mm; C, I, K, L = 0.2 mm; D, F–H, J = 0.5 mm. (A, female, cl 4.2 mm; B–K, female, cl 4.1 mm; all material from Sungei Buloh, Singapore, ZRC). Fig. 5. Caridina propinqua : A, cephalothorax and cephalic appendages; B, pre-anal carina; C, scaphocerite; D, first pereiopod; E, second pereiopod; F, third pereiopod; G, dactylus of third pereiopod; H, fifth pereiopod; I, dactylus of fifth pereiopod; J, diaeresis. Scale bars: A, C = 1 mm; B, D–F, H = 0.5 mm; G, I, J = 0.2 mm. (female, cl. 3.7 mm, Sungei Mandai, Singapore, ZRC). Fig. 6. Caridina propinqua : A, cephalothorax and cephalic appendages; B, scaphocerite; C, mandible; D, maxillula; E, maxilla; F, first maxilliped; G, second maxilliped; H, third maxilliped; I, first pereiopod; J, second pereiopod; K, third pereiopod; L, fifth pereiopod; M, endopod of male first pleopod; N, appendix masculina and appendix interna of male second pleopod. Scale bars: A, B = 1 mm; C–L = 0.5 mm; M, N = 0.2 mm. (male, cl 2.9 mm, Sungai Sedili, Johor, Peninsular Malaysia, ZRC). Remarks. – Cai & Shokita (2006b) recently reviewed the taxonomy of this species and regarded C. hainanensis Liang & Yan, 1983 and C. blancoi Chace, 1997 as its junior synonyms. The forms of the first two pereiopods vary with both location and sex. In the female specimens from Sungei Buloh, Singapore , the carpus of the first and the second pereiopods are 2.2 and 6.3 times as long as high, respectively, those of the female specimens from Sungei Mandai, Singapore , are 2.9 and 7.4 times, respectively, while those of male from Sungai Sedili, Malaysia are 3.4 times and 9.6 times, respectively. The eggs that we measured are also relatively smaller than what has been reported (0.32–0.36 × 0.20–0.22 mm in current study vs. 0.39–0.45 × 0.24–0.27 mm in Hainan (Liang & Yan, 1983) and 0.38–0.48 × 0.25–0.30 mm in the Ryukyu Islands (Cai & Shokita, 2006a)). Johnson (1961) reported the egg size of the present species as 0.54 × 0.36 mm from Malaysia . However, as pointed out in the remarks section under C. johnsoni , new species , Johnson’s (1961) material is probably a mixture of C. propinqua and C. johnsoni (see below). Distribution . – Sri Lanka , India , Malay Peninsula, the Philippines , Japan and China (present study; Cai & Shokita, 2006b).