Caridina peninsularis Kemp, 1918

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 : 280-284

Caridina peninsularis Kemp, 1918

( Figs. 2 , 3 )

Caridina brachydactyla peninsularis Kemp, 1918: 279 , Figs.10a–g [type locality: Patani, southern Thailand and Penang Island, Malaysia]; Johnson, 1961b: 45.

Caridina brachydactyla var. peninsularis – Bouvier, 1925: 155, Figs. 321, 322.

Caridina nilotica var. brachydactyla – Johnson, 1961a: 123.

Caridina simony – Johnson, 1963: 21 (incorrect spelling).

Caridina simoni peninsularis – Johnson, 1966: 422; 1969: 110; Ng & Choy, 1990: 16.

Caridina peninsularis – Cai & Anker, 2004: 237, Fig. 2 ; Wowor et al., 2004: 343, Fig. 6J ; Cai & Shokita, 2006a: 248.

Material examined. – Lectotype: male, 3.8 mm, MNHN, Caridina brachydactyla peninsularis Kemp, 1918 , exchange from Indian Museum , Botanical Garden, Penang, Malaysia, herein designated.

Paralectotypes: 1 male, cl 3.8 mm, 3 females, cl 3.3–5.6 mm, MNHN, data same as lectotype .

Others: Peninsular Malaysia: 1 male, cl 2.9 mm, 7 ovigerous females, cl 4.2–4.8 mm, ZRC 2007.0342 , sandmine at Teok, Nibong area, Batu Ferringhi , Penang, Malaysia , coll. H. H. Tan & S. H. Tan, 8 Jun.1993 ; 2 females, cl 2.6–4.1 mm, ZRC 2007.0343 , stream in Pulau Aur Malaysia ; 1 male, cl 3.1 mm, 2 females, cl 3.6–4.2 mm, 5 ovigerous females, cl 4.2–5.3 mm, ZRC 2007.0344 , Sungai Mupor , Kota Tinggi, Malaysia, 21 Aug.1994 ; 1 male, cl 3.6 mm, ZRC 2007.0345 , Pulau Pemanggil , rocky stream, Malaysia, LMCJ 9628 ; 5 males, cl 2.6–3.2 mm, 6 females, cl 2.5–5.3 mm, ZRC 2007.0346 , Sungai Dohol, Malaysia , coll. H. H. Tan, 24 Feb.1995 ; 1 male, cl 3.6 mm, ZRC 2007.0347 , Terengganu, Pulau Redang, stream on south west slope of eastern ridge, Malaysia , coll. K. Lim, S. Sivasothi, 23 Dec.1992 ; 11 males, cl 3.5–5.5 mm, 1 female, cl 5.4 mm, ZRC 2007.0348 , Gunung Panti, Kota Tinggi, Malaysia , coll. P. K. L. Ng, 1991 ; 8 females, cl 3.5–4.9 mm, ZRC 2007.0349 , stream between Pasir Chayar Hutang and Teluk Kerma, Pulau Redang , Terengganu, Malaysia , coll. K. Lim et al., 23 Jun.1992 ; 3 males, cl 3.1–3.4 mm, 7 females, cl 4.1–5.2 mm, ZRC 1995.50 , Malaysia , coll. K. Lim, Dec.1990 ; 1 male, cl 3.0 mm, 1 ovigerous female, cl 5.0 mm, ZRC 1979.4 .18.75.78, slow, small tidal, stream draining into Sungai Skudai at 7 1/ 2 mile, Johor Bahru-Skudai road, Malaysia, coll. D. S. Johnson, 10 May 1960 ; 1 female, cl 3.5 mm, 5 ovigerous females, cl 4.4–5.4 mm, ZRC 1979.30 – 35 , large slow stream, 7 miles from Kota Tinggi Lombong Road, Johor, Malaysia, no date , 1 male, cl 3.5 mm, 4 females, 3.4–4.4 mm, ZRC 1979.4.18.19–23, S. Mupor at miles 10 marker, Kota Tinggi-Mersing Road, Malaysia, 13 May 1966 ; 2 males, cl 3.4 mm, 1 female, cl 4.0 mm 3 ovigerous females, cl 5.1–5.4 mm, ZRC 2007.0350 , 3 miles from Kota Tinggi , Lombong Kd. large slow stream, Malaysia: Johor, 19 Aug.1960 . Singapore: 3 males, cl 3.3–3.5 mm, ZRC 1974.4.18.4–6, Sungei Seletar, station 3, Singapore , coll. P. Yeo & Kwai Ho, 23 Sep.1959 ; 2 males, cl 3.0– 3.3 mm, 1 female, cl 3.5 mm, ZRC 1979.4.18.1–3, Sg Seletar, Singapore , coll. K. H. Yeo, 23 Sep.1959 ; 2 males, cl 3.3–3.4 mm, 1 female, cl 4.5 mm, 2 ovigerous females, cl 5.3–5.4 mm, ZRC 1979.4.18.8–12, 12 miles from Chua Chu Kang Road, Sg Peng Siang, Singapore, 18 Aug.1961 .

Comparative material examined. – Southern Thailand: 4 males, 9 females, CU 1998.01, Taotong Waterfall , Phangnga, southern Thailand, 22 May 1973 ; 3 females, CU 1998.04, Phangnga, southern Thailand, 8 May 1974 ; 4 specimens, CU 1998.06, Bangpae Waterfall , Phuket, southern Thailand, 28 Mar.1974 ; 10 specimens CU 1998.08, Lam Pee Waterfall , Phangnga, southern Thailand, no date . 3 specimens, CU 1998.10, Tone Na Nua , Phangnga, southern Thailand, 28 Aug.1973 . 11 specimens, CU, southern Thailand, 14 Oct.1967 ; 14 males, cl 2.5–3.4 mm, 12 females, cl 3.3–4.9 mm, 10 ovigerous females, cl 3.6–4.8 mm, southern Thailand, coll. D. Yeo, 21 Feb.2001 ; 2 females, cl 2.5–2.7 mm, CU 2000.06, Thailand: Thonmayom waterfall, Amphoe Ko Chang Trat Province, 9 Dec.1973 ; 3 males, cl 2.8–3.0 mm, 10 ovigerous females, cl 3.3–3.5 mm, CU 2000.12, Thailand: Klong Thom , Amphoe Muang, Phang Nga Province, South Thailand, 12 May 1974 ; 3 females, cl 3.9–5.0 mm, CU 2000.17, Amphoe Ka Po , Ranong, southern Thailand, 9 Dec.1974 . Philippines: 1 female, cl 2.6 mm, FM 2464 , stream near Coron Town , Balisungan, Busuang Island, Philippines, coll. G. Beit, 11 Mar.1991 . Borneo : 3 males, cl 2.1–3.0 mm, 2 females, cl 1.8–1.9 mm, RMNH, 20 km north of Sandakan , Sepilok-laut, near resthouse, Sabah, Malaysia, 5°49'N 118°06'E, coll. J. Huisman & R. de Jong, 3 Nov.1987 ; 2 males, cl 3.8–3.9 mm, 2 females, cl 3.2–4.3 mm, 12 ovigerous females, cl 4.8–6.0 mm, ZRC 2007.0351 , 8.6 km after turning towards Sungai Cina, Matang, 1°39'2.6"N 110°10'44.7"E, after entrance to Matang Reserve, Sarawak, Malaysia, coll. H. H. Tan, 4 Sep.1995 ; 3 males, cl 3.3–3.8 mm, 1 female, cl 4.2 mm, 12 ovigerous females, cl 4.3–5.5 mm, ZRC 2007.0352 , Borneo : Sarawak, Matang area, Kg Tenenggor, 01°37'48.0"N 110°12'51.4'E, coll. H. H. Tan, 4 Sep.1995 ; 9 males, cl 2.7–3.6 mm, 1 female, cl 3.6 mm, 11 ovigerous females, cl 4.0–5.0 mm, ZRC 2007.0353 , Borneo , Sarawak: stream 3.0 km before turnoff to Cape Pelandok and Kg. Pandan, after Lundu Town, drains from Gg. Gading, 1°44'18.5"N 109°52'01.0"E, coll. H. H. Tan, 2 Sep.1996 ; 19 males, cl 2.7–3.7 mm, 5 females, cl 3.7–4.4 mm, 9 ovigerous females, 4.5–5.0 mm, ZRC 2007.0354 , Borneo : Sarawak, Santubong , just before Damai resort area, ca. 100 m after turnoff from road leading from Santubong to Damai, 01°44.83'N 110°18.97'E, pH 5.0, coll. H. H. Tan & P. Yap, 2 Oct.1998 ; 2 ovigerous females, cl 5.3–5.8 mm, ZRC 2007.0355 , Borneo : Sarawak, Lundu area , Sungai Sebiris , 8.7 km towards Sematan on Lundu-Sematan road after T-junction from Batang Kayan ferry point (4 km), 01°41.76'N 109°47.07'E, pH 6.5, coll. H. H. Tan & P. Yap, 2 Oct.1998 ; 1 male, cl 3.0 mm, ZRC 2007.0356 , Borneo , Sarawak: stream near Sungai Tengah Lorong 1, ca. 12.6 km into turnoff towards Singai (eventually leads to Matang), from Bau-Lundu road, 1°32'35.1"N 110°12'49.3"E, coll. H. H. Tan, 2 Sep.1998 ; 1 female, cl 6.0 mm, ZRC 2007.0357 , Borneo , Sarawak: Red Bridge at Matang, 1°36'29.6"N 110°13'25.6"E, pH 6.7, coll. H. H. Tan, 30 Aug.1996 ; 5 males, cl 4.1–4.6 mm, 12 ovigerous females, cl 5.7–6.3 mm, MZB CRU-1637 , A small stream on the road to Beluru , nearby Pekan Bakong, Miri, Sarawak, moderate flowing river with mud-debris substrate and grasses along its bank, 03°50'N 114°10'E, coll. D. Wowor, 11 Sep.1998 ; 1 male, cl 4.0 mm, 5 females, cl 6.6–7.0 mm, 7 ovigerous females, cl 6.4–6.8 mm, MZB CRU-1638 , Sungai Monyet at Lungmanis area , Sandakan District, Sabah, stream between Sandakan and Kota Kinabalu, 60 km from Sandakan town, moderate flowing stream with stones substrate, across forest, 05°43'23.2"N 117°41'07.2"E, pH 7.4, coll. D. Wowor, 27 Sep.1998 ; 1 male, cl 3.6 mm, 2 ovigerous females, cl 5.8–6.0 mm, ZRC 2007.0358 , Borneo , Sarawak: stream at 17.6 km into turnoff towards Singai (eventually leads to Matang), from Bau-Lundu road, 1°33'45.7"N 110°14'19.9"E, coll. H. H. Tan, 2 Sep.1996 , 4 ovigerous females, cl 4.9–5.9 mm, ZRC 2007.0359 , Borneo , Sarawak: Sungai Stuum Muda, 21.1 km before Lundu ferry point at Bg. Kayan, 1°28'51.3"N 109°58'18.1"E, coll. H. H. Tan, 2 Sep.1998 ; 3 males, cl 2.8–3.1 mm, 18 ovigerous females, cl 4.5–5.4 mm, ZRC 2007.0360 , Borneo , Sarawak: stream ca. 4.9km before end of road to Kg. Pueh, near base of Gg. Pueh, 1°48'08.9"N 109°43'41.0"E, coll. H. H,. Tan, 1 Sep. 196 ; 4 ovigerous females, cl 4.5–4.8 mm, ZRC 2007.0361 , 22 km to Senatan from Lundu, draining from Gg Pueh, 1°46'34.9"N 109°44'44.4"E, coll. H. H. Tan, 6 Sep.1995 ; 1 male, cl 3.5 mm, 6 ovigerous females, cl 4.4–5.6 mm, ZRC 2007.0362 , Borneo : Sarawak, 1.3 km before junction to Cina Matang, Kg. Matang, 1°36'1.2"N 110°13'29"E, pH 6.3, coll. H. H. Tan, 4 Sep.1995 ; 2 ovigerous females, cl 4.8–5.7 mm, ZRC 2007.0363 , Sungai Stok Muda , Sarawak, 1°28'51.3"N 109°58'18.1"E, coll. H. H. Tan, 6 Sep.1995 ; 8 males, cl 3.3–4.3 mm, 6 females, cl 3.8–4.3 mm, 4 ovigerous females, cl 4.8–5.0 mm, ZRC 2007.0364 , Brunei: Kg. Lepong Naru, Temburong, 9 Jan.1992 ; 3 females, cl 4.7–5.4 mm, Sarawak: Matang , coll. P. K. L. Ng, 1986 ; 2 males, cl 3.3–3.5 mm, 2 females, cl 5.9–6.2 mm, 8 ovigerous females, cl 5.2–5.4 mm, ZRC 2007.0365 , Brunei: Sungai Baru , Lamunin, coll. S. Choy & K. Lim, 14 May 1993 ; 7 males, cl 2.8–3.2 mm, 6 females, cl 2.7–4.0 mm, 2 ovigerous females, cl 5.3–5.4 mm, ZRC 2007.0366 , Sarawak: Matang , near Park Kuching, coll. S. Choy, 26 Nov.1992 . Java: 6 males, cl 2.6–3.3 mm , 2 females, cl 3.6–4.8 mm, 5 ovigerous females, cl 3.7–4.8 mm, MZB Cr-1068, Bantan, Java, Indonesia, coll. D. I. Hartoto, Aug.1983 ; 1 ovigerous female, cl 5.2 mm, RMNH, Besuki , East Java, Indonesia, coll. Semmelink, 1864 ; 19 males, cl 3.0– 3.7 mm, 8 females, cl 3.2–4.7 mm, 24 ovigerous females, cl 4.0–5.0 mm, MZB CRU-1636 , S. Cihanggasa , Banten, Java, coll. D. Wowor, 16 Aug.1982 . Sumatra: 8 males, cl 2.4–2.8 mm , 6 females, cl 2.4–3.6 mm, 2 ovigerous females, cl 3.6–3.8 mm, RMNH, Way Pisang , Lampang Selatan, coll. Sabar, 24 Jun.1974 ; 10 males, cl 3.0– 3.4 mm, RMNH, Ketang , east coast of Sumatra, Indonesia, 6 Nov.1941 .

Description. – Rostrum horizontal ( Figs. 2A–E ), reaching to or slightly beyond end of scaphocerite, slightly shorter or as long as carapace. Rostral formula: 2–3+15–37(25–32)/5–12, dorsal teeth along entire margin, rarely indistinctly with 1–2 subapical teeth. Antennal spine placed slightly below inferior orbital angle. Pterygostomian margin rounded.

Sixth abdominal somite 0.6 times as long as carapace, 1.9 times as long as fifth somite, slightly shorter than telson. Telson ( Fig. 2F ) 3.2 times as long as wide, terminating in a projection, with 4 pairs of dorsal spinules and 1 pair of dorsolateral spinules; telson with 3 or 4 pairs of distal spines, sublateral pair distinctly longer than intermediate pairs. Preanal ( Fig. 3J ) carina low, no spine.

Eyes well developed, anterior end reaching to 0.7 times length of basal segment of antennular peduncle.Antennular peduncle ( Fig. 3A ) 0.8–0.9 times as long as carapace; basal segment of antennular peduncle longer than combined length of second and third segments, anterolateral angle pointed, reaching to 0.3 times length of second segment, second segment distinctly longer than third segment. Stylocerite reaching to 0.8–0.9 times length of basal segment of antennular peduncle. Scaphocerite ( Fig. 3B ) 3.7 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 ending in a broad triangular projection. Second maxilliped typical, podobranch well developed. Third maxilliped ( Fig. 3I ) reaching to end of second segment of antennular peduncle, with ultimate segment shorter than penultimate segment.

Epipods on first 4 pereiopods. First pereiopod ( Fig. 3C ) reaching to distal end of eyes, merus of first pereiopod 3.3 times as long as wide, slightly shorter than carpus; carpus shorter than chela, 2.5 times as long as high; chela 2.3 times as long as broad, with fingers 1.6 times as long as palm. Second pereiopod ( Fig. 3D ) reaching beyond end of second segment of antennular peduncle, merus 4.9 times as long as broad; carpus of second pereiopod 4.9 times as long as high, 1.3 times as long as chela, chela 2.6 times as long as wide, fingers 1.4 times as long as palm. Third pereiopod ( Figs. 3E, F ) reaching beyond end of antennular peduncle, propodus 14 times as long as broad, 5.6 times as long as dactylus; dactylus 3.0 times as long as wide (spines included), terminating in 2 claws, with 4–6 accessory spines on flexor margin. Fifth pereiopod ( Fig. 3G, H ) reaching beyond end of scaphocerite, propodus 17 times as long as broad, 4.8 times as long as dactylus; dactylus 3.5 times as long as wide (spinules included), with 38–42 spinules on flexor margin.

Endopod ( Fig. 2G ) of male first pleopod subtriangular, 1/4 length of exopod, appendix interna elongated, with most of its length reaching beyond end of endopod. Appendix masculina ( Fig. 2H ) of male second pleopod 2/3 times length of endopod, appendix interna stout.

Uropodal diaeresis ( Fig. 3K ) with 13–14 movable spinules.

Ovigerous females with eggs sized 0.40–0.42 × 0.25–0.30 mm.

Habitat. – Commonly found in low-salinity brackish waters and in freshwater systems subject to tidal influence.

Remarks. – Johnson (1963) synonymised many species allied with C. nilotica under C. simoni , including C. brachydactyla peninsularis . He stated that “Kemp’s subspecies peninsularis can be recognized as valid, under the name C. simoni peninsularis .” This was followed by Johnson (1963, 1966), Ng & Choy (1990) and Ng (1990). Tiwari & Pillai (1971), however, pointed out that “ C. brachydactyla and C. simoni are distinct taxa, differing from each other in a number of important characters. The major points of difference between the two are the structure of rostrum and first pleopod” and reassigned peninsularis back as a subspecies of brachydactyla . We agree with Tiwari & Pillai (1971) in recognizing the two as separate taxa, but we believe that peninsularis should be accorded a full species status as the differences in the rostrum (teeth throughout the upper margin vs. with distinct apical teeth in C. brachydactyla ) and the absence of a large distal spine in male specimen (vs. present in C. brachydactyla ) are very distinct and cannot be accounted for by infraspecific variation.

Distribution. – Greater Sunda Islands and the Philippines (present study).

Figures

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. 10. Caridina thambipillaii: A, cephalothorax and cephalic appendages; B, first pereiopod; C, second pereiopod; D, third pereiopod; E, dactylus of third pereiopod; F, endopod of male first pleopod; G, male second pleopod. Scale bars: A = 1 mm; B–D = 0.5 mm; E – G=0.2 mm. (male, cl 3.3 mm, Sungai Stunggang, Sarawak, East Malaysia, 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).