Caridina ensifera Schenkel, 1902

Cai, Yixiong & Wowor, Daisy, 2007, Atyid Shrimps From Lake Poso, Central Sulawesi, Indonesia With Description Of A New Species (Crustacea: Decapoda: Caridea), Raffles Bulletin of Zoology 55 (2), pp. 311-320 : 311-314

Caridina ensifera Schenkel, 1902

( Figs. 1 , 2 )

Caridina ensifera Schenkel, 1902: 490 , Pl. 8: Figs. 1a–c , 4d [type locality: Danau Poso, Sulawesi (Celebes), Indonesia]; Roux, 1904: 553; Bouvier, 1925: 163, Figs. 344–352; Chace, 1997: 9.

Material examined. – Lectotype: male, cl 3.9 mm, BMNH-1a, Lake Poso , Celebes (Sulawesi), Indonesia, coll. Sarasin, no date indicated.

Paralectotypes: 5 males, cl 3.1–3.5 mm, 10 females, cl 3.0– 5.3 mm, BMNH-1a, same data as lectotype ; 6 males, cl 3.1–3.9 mm, 10 females, cl 3.0– 5.3 mm, BMNH 1 a, Lake Poso , central Sulawesi, Indonesia, coll. Sarasin ; 2 specimens, cl 5.1 mm, MNHN 721 , Lake Poso , Sulawesi, exchanged from Museum of Basel, 1904 .

Other materials: 1 male, cl 4.0 mm, ZRC 2007.0463 , Lake Poso at Tentena , central Sulawesi, 0–1 meter depth, coll. H. Larson, 6 Sep.1989 ; 9 males, cl 2.5–4.3 mm, 3 females, cl 2.5–3.3 mm, ZRC 2007.0464 , Sungai Poso at the outlet of Lake Poso, across the new bridge at rocky cliff, Tentena , Kab. Poso , Sulawesi Tengah, Indonesia, coll. C. Schubart et al., 22 Jan.2000 ; 17 males, cl 3.2–3.8 mm, 10 females, cl 3.5–4.8 mm, 2 ovigerous females, cl 3.7–4.7 mm, eggs 0.55 × 0.90 mm, MZB CRU-1639 , west coast of Lake Poso at Desa Taipa area, Kab. Poso , Sulawesi Tengah, rocky shore with sand substrate, coll. C. Schubart et al., 22 Jan.2000 ; 4 males, cl 3.6–3.7 mm, 3 females, cl 3.1–4.4 mm, 2 ovigerous females, cl 3.4 mm, ZRC 2007.0465 , east coast of Lake Poso at Desa Besuna, Kab. Poso , Sulawesi Tengah, rocky area, coll. C. Schubart et al., 22 Jan.2000 ; 13 males, cl 2.3–4.2 mm, 8 females, cl 3.3–4.3 mm, MZB CRU-1640 , beach of Lake Poso at Desa Tindolo, Kab. Poso , Sulawesi Tengah, coll. C. Schubart et al., 22 Jan.2000 ; 4 males, cl 3.3–4.0 mm, 9 females, cl 3.4–4.6 mm, 5 ovigerous females, cl 4.2–4.6 mm, ZRC 2007.0466 , south coast of Lake Poso at Desa Pendolo, Kab. Poso , Sulawesi Tengah, white sand with gravel substrate, coll. C. Schubart et al., 22 Jan.2000 ; 1 male, cl 4.1 mm, ZRC 2007.0467 , along Sungai Poso near the outlet of Lake Poso, up to the jetty across Hotel Pamona Indah at the coast of Lake Poso , Tentena , Kab. Poso , Sulawesi Tengah, Indonesia, sandy substrate with clear water, coll. C. Schubart et al., 20 Jan.2000 ; 3 males, cl 3.8–4.6 mm, 4 females, cl 3.0– 5.1 mm, 1 ovigerous female, cl 5.0 mm, ZRC 2007.0468 , 0–1 m, Lake Poso at Tentena , Sulawesi, Indonesia, mud and coarse gravel substrate, coll. H. Larson, 6 Sep.1989 ; 1 male, cl 4.0 mm, ZRC 2007.0469 , 0–1 m, Lake Poso at Tentena , Sulawesi, Indonesia, mud and coarse gravel substrate, coll. H. Larson, 6 Sep.1989 ; 7 males, cl 4.2–4.6 mm, 4 females, cl 3.0– 4.8 mm, 2 ovigerous females, cl 4.1–4.7 mm, ZRC 2007.0470 , east shore of Lake Poso , between Tentena and Peura, Sulawesi, coll. M. Kottelat, 24 Jun.1988 .

Description. – Rostrum very long, reaching far beyond end of scaphocerite, ascendant in anterior 2/3, armed dorsally with 9–15 teeth in posterior 1/3 to1/2, including 1–3 teeth on carapace posterior to orbital margin, without subapical teeth, armed ventrally with 14–26 teeth. Antennal spine placed lower than inferior orbital angle. Pterygostomian margin obscurely angular.

Sixth abdominal segment ca. 0.8 times as long as carapace, longer than telson, 2.6 times as long as fifth segment. Preanal carina with a spine. Telson 3.6 times as long as wide, not terminating in a projection, with 3–5 pairs of dorsal spinules on distal half of telson, placed near lateral edges; with about 3 pairs of distal spines, lateral pair of distal spines distinctly longer than intermediates.

Eyes well developed, anterior end reaching to 0.7 times length of basal segment of antennular peduncle. Antennular peduncle as long as carapace; basal segment of antennular peduncle as long as combined length of second and third segment, anterolateral angle of basal segment reaching to 0.2 times length of the second segment, second segment about 2 times as long as third segment. Stylocerite reaching to 0.8 times length of basal segment of antennular peduncle. Scaphocerite 4.3 times as long as wide.

Incisor process of mandible ending in irregular teeth, molar process truncated. Lower lacinia of maxillula broadly rounded, upper lacinia elongated, with a number of distinct teeth on inner margin, palp slender. Upper endites of maxilla subdivided, palp stout and short, scaphognathite tapering posteriorly with numerous long, curved setae at posterior end. Palp of first maxilliped broad, ending in a triangular projection. Podobranch of second maxilliped reduced to a lamina. Third maxilliped reaching to end of second segment of antennular peduncle, with ultimate segment as long as penultimate segment.

Epipods on first two pereiopods. First pereiopod reaching to distal end of eye stalk, merus 2.5 times as long as wide, shorter than carpus; carpus slightly excavated anteriorly, 3.0 times as long as high; chela 2.2 times as long as broad, fingers as long as palm. Second pereiopod reaching beyond end of second segment of antennular peduncle, merus 4.3 times as long as wide, shorter than carpus; carpus 6.5 times as long as high, 1.4 times as long as chela; chela 3.2 times as long as broad, fingers 1.1–1.4 times as long as palm. Third pereiopod reaching to end of second segment of antennular peduncle; propodus 13 times as long as wide, 3.2 times as long as dactylus; dactylus 4.6 times as long as wide (spines included), with 7–9 spines on flexor margin. Fifth pereiopod reaching beyond end of basal segment of antennular peduncle; propodus 12 times as long as wide, 2.6 times as long as dactylus; dactylus 4.3 times as long as broad, with 50 spinules on flexor margin.

Endopod of male first pleopod sub-rectangular, 0.2 times length of exopod, without appendix interna. Appendix masculina of male second pleopod short, reaching to 0.4 times length of endopod, appendix interna half length of appendix masculina.

Uropodal diaeresis with 10 movable spinules.

Eggs 0.9 × 0.6 mm.

Colour. – A single specimen from Lake Poso, had the following colour note: “transparent finely spectra, blue-red n-shape on brachiostegal region, blue spot on distal exopod of uropod-conspicuous” (H. Larson, on collection label)

Habitat. – Lakes. This species is common in Lake Poso. It occupies a wide range of habitats, living among rocky shores, sandy substrates and among algae.

Remarks. – With regard to the form of the rostrum, C. ensifera is very similar to C. endehensis De Man, 1892 (cf. Chace, 1997: 8, Fig. 3 ), which is distributed in the Philippines and Indonesia. It can easily be distinguished by its more elongated carpus of the first pleopod (3.1 times as long as wide vs. length shorter than wide); the fewer number of epipods on the pereiopods (epipods on the first two pereiopod vs. on the first four); and the structure of the telson (not terminating in a projection vs. terminating in a posteromedian projection)

Distribution. – Endemic to Lake Poso in central Sulawesi, Indonesia.

Figures

Fig. 1. Caridina ensifera: 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. Scale bars: A, B = 1 mm; C–J = 0.5 mm. (ZRC).

Fig. 2. Caridina ensifera: A, telson; B, distal portion of telson; C, third pereiopod; D, dactylus of third pereiopod; E, fifth pereiopod; F, dactylus of fifth pereiopod; G, endopod of male first pleopod; H, appendix masculina and appendix interna of male second pleopod; I, preanal carina; J, diaeresis. Scale bars: A, C, E, I = 0.5 mm; B, G, H, J = 0.2 mm; D, F = 0.1 mm. (ZRC).

Fig. 4. Caridina longidigita, new species: A, cephalothorax and cephalic appendages; B, telson; C, distal portion of telson; D, scaphocerite; E, mandible; F, maxillula; G, maxilla; H, first maxilliped; I, second maxilliped; J, third maxilliped; K preanal carina; L, diaeresis. Scale bars: A, D = 1 mm; B, E–K = 0.5 mm; C, L = 0.2 mm. (paratype, ZRC 2007.0748).

Fig. 3. Caridina sarasinorum: 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, endopod of male first pleopod; J, appendix masculina and appendix interna of male second pleopod; K, preanal carina; L, diaeresis. Scale bars: A = 1 mm; B, F, H, I, J, L = 0.2 mm; C–E, G, K = 0.5 mm. (lectotype, BNHM).