Caridina temasek Choy & Ng, 1991

Cai, Yixiong, Ng, Peter K. L. & Choy, Satish, 2007, Freshwater Shrimps Of The Family Atyidae (Crustacea: Decapoda: Caridea) From Peninsular Malaysia And Singapore, Raffles Bulletin of Zoology 55 (2), pp. 277-309 : 297-301

Caridina temasek Choy & Ng, 1991

( Figs. 13 , 14 )

Caridina cf. babaulti Johnson, 1961:136 , Fig.21–24 [not Caridina babaulti Bouvier, 1918 )

Caridina sp. Ng, 1990: 200 ; Ng & Tan, 1991: 120.

Caridina temasek Choy & Ng, 1991: 265 , Figs.1–5 [type locality: Forest stream in Sime road, Singapore]; Wowor et al., 2004:343, Fig. 7I .

Material examined. – Holotytpe: ovigerous female, cl 3.5 mm, ZRC 2007.0396, Sime Road, Singapore, coll. P. K. L. Ng & K. K. P. Lim, Aug.1990. Others : Singapore : 3 males, cl 2.6–2.7 mm, 1 ovigerous female, cl 3.9 mm, eggs 0.85 × 0.60 mm, Sime Road , forest stream, coll. K. Yong, & K. L. Yeo, 17 Apr.1990 ; 3 males, cl 2.1–2.3 mm, 2 females, cl 3.0– 3.2 mm, 3 ovigerous females, cl 3.0–4.0 mm, Stream in Sime Road , Singapore, coll. Y. Y. Lim, 19 Apr.1990 . Malaysia: 5 males, cl 2.3–2.7 mm , 7 females, cl 2.7–3.1 mm, 6 ovigerous females, 2.8–3.7 mm, Sungai Semalok , between Mawai & Tg. Sedili, Johor, Malaysia, coll. P. K. L. Ng, 22 Apr.1992 ; 3 males, cl 2.1–2.4 mm, 6 females, cl 2.6–3.5 mm, 14 ovigerous females, cl 3.1–3.8 mm, stream after K. Brang towards Kuala Terengganu, Malaysia, pH 5.7, 25.9 C, coll. P. K.L. Ng, 19 Mar.1992 ; 1 male, cl 3.5 mm, Sekayu Waterfall , Malaysia, coll. H. H. Tan, 17 Jun.1995 ; 2 specimens, Johor, Kota Tinggi , Sungai Mupor, along Johor Bahru-Kuantan highway, Malaysia, coll. M. Kottelat & K. Lim, 22 Jan.1991 ; 1 male, cl 2.4 mm, 1 ovigerous female, cl 3.5 mm, Sungai Ambat , 61 km from Kota Tinggi on road to Mersing, Johor, Malaysia, coll. M. Kottelat & P. K. L. Ng, 24 Jul.1992 ; 2 females, cl 2.8–3.3 mm, 1 ovigerous female, cl 3.2 mm, ZRC.1979.4.17.67–69, Mawai, Malaysia, 9 Oct.1959 ; 2 females, cl 3.2–3.8 mm, 4 ovigerous females, cl 3.7–4.0 mm, Sungai Machap , under bridge between Air Hitam and Simpang, Johor, Malaysia, coll. Renggam, 18 Aug.1991 ; 4 females, cl 2.5–2.8 mm, 3 ovigerous females, cl 2.7–3.1 mm, Gunung Panti , Kota Tinggi, Malaysia, coll. P. K. L. Ng, 1991 ; 5 males, cl 2.0–2.2, 12 females, cl 2.4–3.4 mm, 12 ovigerous females, cl 2.7–3.4 mm, stream on logging track, Gunung Panti, Johor, Malaysia, no date ; 8 specimens, blackwater stream, Batu Arang , Kuala Lumpur, Malaysia, coll. S. Choy et al., 6 Nov.1991 ; 1 ovigerous female, cl 4.7 mm, ZRC 1995.507 , Johor, Sungai Semberong , Malaysia, coll. C. Yong, 13 Apr.1990 ; 2 females, cl 3.0– 3.2 mm, 1 ovigerous female, cl 2.8 mm, slow out flow stream of Lake Chin Chin , Malacca, Malaysia, coll. D. S, Johnson, 29 Oct.1963 ; 1 female, cl 3.5 mm, Mawai , Johor, Malaysia, 18 Jul.1961 ; 1 female, cl 3.1 mm, ZRC 1979.4 .11.1, S. Semalok, 9 miles from Kota Tinggi , Mawai Road, Malaysia, coll. D. S. Johnson, 1 Apr.1961 ; 4 females, cl 2.5–3.0 mm, ZRC 1979.4.11.7–10, slow outflow stream of Lake Chin Chin , Malacca, Malaysia, 29 Oct.1963 ; 1 ovigerous female, cl 3.5 mm, one female, in poor condition, ZRC 1979.4 .11.12, outflow stream of Ayer Keroh Reservoir , Malacca, Malaysia, coll. D. S. Johnson, 6 Jan.1956 ; 2 males, cl 2.7–2.8 mm, 4 females, cl 3.3–3.9 mm, 5 ovigerous females, cl 3.0– 3.7 mm, Malaysia , 2 males, cl 2.7–2.8 mm, 4 female, cl 3.3–3.9 mm, 5 ovigerous females, cl 3.0– 3.7 mm, Perak, Malaysia, H. H. Ng, 16 Jun.1997 .

Comparative material examined. – Southern Thailand: 8 males, cl 20–25 mm , 18 females, cl 2.4–3.3 mm, ZRC 2007.0408 , Narathiwat Province, stream at bridge about 1 km south of bridge on Mae Nam Road Tod Deng , about 5 km north of Narathiwat, coll. M. Kottelat, 3 Nov.1995 ; 1 female, cl 3.4 mm, ZRC 2007.0409 , Narathiwat Province, 10 km north of Bocho on Road Narathiwat-Sai Buri , coll. M. Kottelat, 1 Nov.1995 ; 1 male, cl 2.0 mm, 6 females, cl 1.8–3.0 mm, 3 ovigerous females, cl 2.9–3.9 mm, CU2000.03; 1 ovigerous female, cl 3.0 mm, CU2000.07; 1 ovigerous female, cl 2.7 mm, CU2000.08; 12 females, cl 2.9–3.7 mm, ZRC 2007.0410 ; Thailand: Mae Sot, Mae Nam Moi , border with Myanmar , Karen State , 16°41.22'N 98°30.90'E, coll. H. H. Tan, 26 May 1999 ; 16 females, cl 2.6–3.7 mm, 1 ovigerous female, cl 3.2 mm, ZRC 2007.0411 , Thailand: south Thailand, Songkhla Province, Nam Tok Khao Chong , km 25 on road to Trang from Phattalung, 07°39.71'N 100°02.33'E, coll. H. H. Tan et al., 26 Oct.1998 . Borneo : 19 males, cl 2.0– 2.4 mm, 15 females, cl 2.3–3.4 mm, 9 ovigerous females, cl 3.0– 3.6 mm, ZRC 2007.0412 , Kalimantan Barat, Kabupaten Pontianak: Sungai Belado , clear water hill stream, at base of Gg Kloncet , at km 67 on Pontianak on Patiana-Anjungan road, Kg. Anjungan, 00°21.02'N 109°11.08'E, coll. H. H. Tan et al., 28 Apr.1998 ; 3 ovigerous females, cl 3.1–3.5 mm, ZRC 2007.0413 , Kalimantan Barat, Kabupaten Sanggau: clear fast flowing stream at km 249 Pontianak on Sosok-Sanggau road, 00°09.64'N 110°29.46'E, H. H. Tan et al., 26 Apr.1998 ; 1 male, cl 2.6 mm, ZRC 2007.0414 , Kalimantan Barat, Kabupaten Sanggau: blackwater stream at km 352 Pontianak on Sekadau-Sintang road, 00°00.44'N 111°14.38'E, coll. H. H. Tan et al., 25 Apr.1998 ; 1 male, cl 2.1 mm, 25 females, cl 2.0– 3.4 mm, 12 ovigerous females, cl 3.1–4.0 mm, eggs 0.8–9.3 × 0.6 mm, ZRC 2007.0415 , Kalimantan Barat, Kabupaten Pontianak: clear water hill stream and paddy ditch at base of Gg. Semahung, ca. 13.8 km into side road from Pahuman , 00°14.79'N 109°11.08'E, pH 6.6, coll. H. H. Tan, 27 Apr.1998 ; 2 females, cl 2.8–4.2 mm, ZRC 2007.0416 , Kalimantan Barat, Kabupaten Pontianak: Sungai Belado , clear water hill stream ar base of Gg. Kloncet at km 67 Pontianak on Pontianak-Anjungan road, Kg. Anjungan , 00°21.02'N 109°11.08'E, pH 6.6, coll. H. H. Tan et al., 28 Apr.1998 ; 1 ovigerous female, cl 3.5 mm, ZRC 2007.0417 , Kapuas, Kalimantan Barat, Desa Tekalong , rocky stream 37.8 km (39km milestone to Putussibau ) from Putussibau , rubber plantation, 8–10m in width, 0.5–1 m in depth, hard bank with patches of grasses, sand to big gravel substrat, fast flowing clear mountain stream, cool water, 00°34'22.1"N 112°50'36.8"E, coll. Y. Y. Goh, 8 May 1998 ; 12 females, cl 3.0– 3.7 mm, 7 ovigerous females, cl 3.8–4.1 mm, eggs 0.9 × 0.6 mm, ZRC 2007.0418 , Sungai Kubas, Sarawak, Borneo , coll. P. K. L. Ng, 25 Jun.1999 ; 23 females, cl 2.4–4.1 mm, 34 ovigerous females, cl 3.3–3.7 mm, ZRC 2007.0419 , Kalimantan Barat, Kabupaten Sintang: clear flowing stream ca. 2–3 km before Nanga sayan on Nanga Pinoh-Nanga Sayan road, 00°42.15'S 111°41.50'E, coll. H. H. Tan et al., 24 Apr.1998 ; 11 females, cl 2.7–3.7 mm, 2 ovigerous females, cl 3.0–4.0 mm, ZRC 2007.0420 , Sungai Temunyuk, small sandy-rocky stream 67.8km (69 km milestone) from Putussibau , rubber plantation, sand and mud bank with grass, fast flowing at some places, 1–5 m in width, 0.5–1 m in depth, clear water, 00°27'42.2"N 112°38'45.7"E, pH 6.8, coll. Y. Y. Goh, 8 May 1998 ; 1 male, cl 2.8 mm, 6 females, cl 2.7–3.7 mm, 11 ovigerous females, cl 3.3–3.8 mm, ZRC 2007.0421 , Kalimantan Barat, Kabupaten Sanggau, clear water stream at km 325 Pontianak on Sekadau-Sintang road, at Gonis Butun , Kec. Sekadau Ilir , 00°01.97'N 111°06.91'E, pH 6.0, coll. H. H. Tan, 25 Apr.1998 ; 9 females, cl 3.0–4.0 mm, 6 ovigerous female, cl 3.3–3.6 mm, Borneo, Sarawak: Bau , stream next to Fairy Caves , coll. P. K. L. Ng, 24 Jun.1996 ; 6 females, cl 3.6–4.1 mm, 4 ovigerous females, cl 3.4–4.0 mm, ZRC 2007.0422 , Borneo, Sarawak: Sungai Kuhas tributary (feeder stream) 0.5km towards Kg. Lanchang, 6.9 km left at Tebelu Tebakang turnoff, 5.8 km into right trail, 1°09'23.1"N 110°29'29.9"E, coll. H. H. Tan, 31 Aug.1996 ; 2 females, cl 3.2–3.7 mm, ZRC 2007.0423 , Sarawak, no date ; 6 females, cl 2.9–3.2 mm, 13 ovigerous females, cl 3.4–3.8 mm, ZRC 2007.0424 , Kalimantan Timur, Sungai Semayang at Desa Semayang , coll. H. H. Tan & D. Wowor, 8 Nov.1999 .

Description. – Rostrum ( Figs. 13A , 14A, B ) straight, or slightly sigmoid, reaching near end of basal segment of antennilar peduncle or slightly beyond end of second segment. Rostral formula: 4–6+10–14/2–6. Suborbital angle acute, distinctly separated from antennal spines; pterygostomian margin rounded.

Sixth abdominal somite 1.5 times as long as high, 0.6 times length of carapace, 1.6 times as long as fifth somite, slightly shorter than telson. Telson ( Fig. 14C ) 3.0 times as long as wide, distal margin rounded, not terminating in a projection, with 3 to 4 pairs of dorsal spinules and one pair of dorsolateral spinules; distal end with 3 or 4 pairs of spines, lateral pair slightly longer than intermediate pairs. Preanal carina ( Fig. 13I ) triangular, no spine or with a very tiny spine.

Eyes well developed, anterior end reaching to 0.7 times length of basal segment of antennular peduncle.Antennular peduncle 0.8 times as long as carapace; basal segment of antennular peduncle longer than combined length of second and third segments, anterolateral angle reaching to 0.3 times length of the second segment, second segment distinctly longer than third segment. Stylocerite reaching to 0.8 times length of basal segment of antennular peduncle. Scaphocerite 3.6 times as long as wide.

Incisor process of mandible ending in irregular teeth, molar process truncated. Lower lacinia of maxillula broadly rounded, subtriangular, upper lacinia elongated, with a number of distinct teeth on inner margin, palp slender. Upper endites of maxilla subdivided, palp short, scaphognathite tapering posteriorly with numerous long, curved setae at posterior end. Palp of first maxilliped ( Fig. 13B ) ending in a fingerlike projection. Second maxilliped typical, podobranch well developed. Third maxilliped reaching to end of scaphocerite, with ultimate segment shorter than penultimate segment.

Epipods well developed on first 2 pereiopods, reduced in third and fourth. First pereiopod ( Figs. 13C , 14E, F ) reaching to end of basal segment of antennular peduncle; merus 2.6 times as long as broad, slightly shorter than carpus; carpus excavated anteriorly, shorter than chela, 3.1 times as long as high; chela 2.9 times as long as broad; fingers 1.4 times as long as palm. Second pereiopod ( Figs. 13D , 14G ) reaching beyond end of second segment of antennular peduncle; merus shorter than carpus, 5.4 times as long as broad; carpus 1.4 times as long as chela, 7.2 times as long as high; chela 3.8 times as long as broad; fingers 1.3 times as long as palm. Third pereiopod ( Figs. 13E, F , 14H, I ) reaching to end of scaphocerite, propodus 13 times as long as broad, 4.1 times as long as dactylus; dactylus 4.3 times as long as wide (spines included), terminating in a claw, with 8 accessory spines on flexor margin. Fifth pereiopod ( Figs. 13G, H , 14J, K ) reaching to end of second segment of antennular peduncle, propodus 14 times as long as broad, 2.8 times as long as dactylus; dactylus slender, 5.2 times as long as wide (spinules included), terminating in a claw, with 55–72 spinules on flexor margin.

Endopod of male first pleopod subtriangular, twice as long as wide, reaching to 1/4 length of endopod, appendix interna reaching beyond end of endopod by most of its length. Appendix masculina of male second pleopod slender, reaching to half length of exopod.

Uropodal diaeresis ( Fig. 14L ) with 12–16 movable spinules.

Ovigerous females with egg size 0.70–0.85 × 0.44–0.54 mm.

Habitat. – Streams and lakes.

Remarks. – In the form of the rostrum, slender pereiopods and egg size, C. temasek can easily be confused with C. excavatoides and C. tonkinensis . But it can readily be differentiated from the latter two species by the structure of the endopod of the male first pleopod, which has a distinct appendix interna (vs. absent).

Johnson (1961) doubtfully referred one ovigerous female and one non-ovigerous female “from a rather fast stream flowing out of Ayer Keroh Reservoir, Malacca ” to C. babaulti . According to his description, they seem to belong to the present species; and a re-examination of the specimens (ZRC 1979.4.11.12) confirms this. Caridina temasek can readily be distinguished from C. babaulti by the absence of a pterygostomian spine. The present study shows that C. temasek has a wider distribution than previously recorded from southern Thailand at the north to the West Kalimantan, Indonesia in the south.

Distribution. – The Malay Peninsula, Sarawak and West Kalimantan (present study).

Figures

Fig. 13. Caridina temasek: A, cephalothorax and cephalic appendages; B, first pereiopod; C, first pereiopod; D, second pereiopod; E, third pereiopod; F, dactylus of third pereiopod; G, fifth pereiopod; H, dactylus of fifth pereiopod; I, preanal carina. Scale bars: A = 1 mm; B–E, F, I = 0.5 mm; F, H = 0.1 mm. (ovigerous female, cl 3.9 mm, Sime Road, Singapore, ZRC).

Fig. 14. Caridina temasek Penang: A, B, cephalothorax and cephalic appendages; C, distal portion of telson; D, preanal carina; E, F, first pereiopod; G, second pereiopod; H, third pereiopod; I, dactylus of third pereiopod; J, fifth pereiopod; K, dactylus of fifth pereiopod; L, uropodal diaeresis. Scale bars: A, B = 1 mm; E–H, J = 0.5 mm; C, I, L, K = 0.2 mm. (female, cl 3.4 mm, Penang, Peninsular Malaysia, ZRC).

Fig. 1. Map of Peninsular Malaysia and Singapore.

Fig. 2. Caridina peninsularis: A–E, cephalothorax and cephalic appendages; F, distal portion of telson; G, endopod of male first pleopod; H, appendix masculina and appendix interna of male second pleopod. Scale bars: A–F = 1 mm; G–H = 0.1 mm. (A, female, cl 4.6 mm; B, F, female, cl 5.0 mm; C, female, cl 4.3 mm; D, female, cl 3.6 mm; E, female, cl 4.0 mm; G, H, male, cl 2.9 mm; all material from Penang, Peninsular Malaysia, ZRC).

Fig. 3. Caridina peninsularis: A, antennular peduncle; B, scaphocerite; C, first pereiopod; D, second pereiopod; E, third pereiopod; F, dactylus of third pereiopod; G, fifth pereiopod; H, dactylus of fifth pereiopod; I, third maxilliped; J, preanal carina; K, diaeresis. Scale bars: A, B = 1 mm; C–E, G, I = 0.5 mm; F, H = 0.1 mm; K = 0.2 mm. (female, cl 5.0 mm, Penang, Peninsular Malaysia, ZRC).

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. 7. Caridina sumatrensis: A, cephalothorax and cephalic appendages; B, distal portion of telson; C, first pereiopod; D, second pereiopod; E, third pereiopod; F, dactylus of third pereiopod; G, fifth pereiopod; H, dactylus of fifth pereiopod; I, male first pleopod; J, male second pleopod. Scale bars: A = 1 mm; C–E, G = 0.5 mm; B, F, H, I, J = 0.2 mm. (male, cl 3.7 mm, Sungai Telor, Peninsular Malaysia, ZRC).