Caridina butonensis, Klotz, Werner & Rintelen, Kristina Von, 2013

Klotz, Werner & Rintelen, Kristina Von, 2013, Three new species of Caridina (Decapoda: Atyidae) from Central Sulawesi and Buton Island, Indonesia, and a checklist of the islands’ endemic species, Zootaxa 3664 (4), pp. 554-570 : 564-568

Caridina butonensis n. sp.

( Figs. 5 A–M, 6A–I, color plate 1B)

Material examined. Holotype male, cl 3.31 mm (MZB Cru 3182), Indonesia: Pulau Buton, Lacurisa, 05°11.292'S 122°52.943'E, 291 m asl, small stream, conductivity 480 µs/cm, pH 7.85, water temperature 24.5°C, leg. H.G. Evers, 0 1 Oct. 2010. Paratypes: 2 females, cl 3.13–3.57 mm, 4 males, cl 2.83–3.23 mm (MZB Cru 3183), same data as holotype; 1 ovigerous female, cl 3.79 mm, 3 females, cl 3.11–3.78 mm, 5 males, cl 2.18–3.25 mm (ZMB 28094; Präp. Nr. 5030–5034) same data as holotype; 4 females, cl 2.97–3.79 mm (MZB Cru 3184), Indonesia: Pulau Buton, Desa Susu, 0 5°14.511'S 122°47.753 'E, 25 m asl, small stream near Susu village, water temperature 26.8°C, pH 8.3, conductivity 683 µs/cm, leg. H.G. Evers, 0 1 Oct. 2010; 3 ovigerous females, cl 3.58– 3.93 mm, 2 females, cl 3.34–3.37 mm, 1 male, cl 2.85 mm (ZMB 28095) Indonesia: Pulau Buton, Desa Susu, 05°14.511'S 122°47.753'E, 25 m asl, small stream near Susu village, water temperature 26.8°C, pH 8.3, conductivity 683 µs/cm, leg. H.G. Evers, 0 1 Oct. 2010. 1 ovigerous female, cl 3.76 mm, 1 female 3.97 mm (OUMNH.ZC.2012-05-009), Indonesia: Pulau Buton, Desa Susu, 05°14.511'S 122°47.753'E, 25 m asl, leg. H.G. Evers, 0 1 Oct. 2010.

Comparative material examined. Caridina opaensis J. Roux, 1904 . 2 females, cl 3.4 and 3.7 mm (ZMB 29338), Indonesia: Southeast Sulawesi , stream in Pruiala (Mulyocinta), N of Aopa area, 04°3.67’S 122°6.845’E, leg. M. Glaubrecht et al., 31 May 2005; 1 male, cl 3.1 mm, 3 females, cl 4.1–4.4 mm (ZMB 29008), Indonesia: Southeast Sulawesi , Benua River, northern arm, 04°13.388’S 122°6.397’E, leg. M. Glaubrecht et al., 31 May 2005; 3 males, cl 3.8–4.0 mm, 3 females 4.1–4.5 mm (ZMB 29349), Indonesia: Southeast Sulawesi , Poniponiki, NW of Raterate, road Kendari-Kolaka, 04°2.115’S 121°52.816’E, leg. M. Glaubrecht et al., 30 May 2005.

Description. Cephalothorax and cephalic appendages. Carapace length 2.18–3.79 mm (median 3.16 mm). Rostrum ( Fig. 5 A–D) straight, short, slightly concave above eyes in most specimens, distal end truncated, reaching to or just to end of basal segment of antennular peduncle, 0.32–0.40 (median 0.35) times as long as carapace. Rostral dorsal teeth situated near mid length of rostrum, ventral teeth very small, located subventral on truncated distal margin, occasionally 1 ventral tooth on ventral margin. Rostrum formula 0 + 3–9(4–7) / 1–8(3–6). Inferior orbital angle with a small antennal spine. Pterygostomian angle rounded. Eyes well developed with globular cornea. Antennular peduncle 0.78–0.82 times as long as carapace in males, 0.59–0.66 times as long as carapace in females, first segment 1.81-2.13 (median 1.98) times as long as second segment, second segment 1.45–2.06 (median 1.60) times length of third segment. Stylocerite reaching to, and 0.74–0.92 (median 0.83) times of basal segment of antennular peduncle. Scaphocerite ( Fig. 5 G) 3.15–3.63 (median 3.43) times as long as wide.

Abdominal somites, telson and uropods. Sixth abdominal somite 0.49–0.56 (median 0.52) times carapace length, 1.47–1.79 (median 1.63) times as long as fifth somite, 0.85–0.92 (median 0.90) times as long as telson. Telson length ( Fig. 5 E) 3.25 (n=1) times as long as proximal wide, distal margin convex without median projection, with 3–4 pairs of dorsal spinules and one pair of dorsolateral spinules; distal end with 7–8 spines, lateral pair longest, sublateral pair slightly shorter than lateral and inner spines. Preanal carina ( Fig. 5 N) low. Uropodal diaeresis ( Fig. 5 F) with 15–18 movable spinules, outermost one shorter than lateral angle.

Mouthparts and branchiae. Incisor process of mandible ending in irregular teeth, molar process truncated ( Fig. 5 H). Lower lacinia of maxillula broadly rounded, upper lacinia elongate, with numerous distinct teeth on inner margin, palp slender with few simple setae at tip ( Fig. 5 I). Upper endites of maxilla subdivided palp slender, scaphognathite tapering posteriorly, fringed with long, curved setae at posterior margin ( Fig. 5 J). Palp of first maxilliped ending in a triangular extension ( Fig. 5 K). Podobranch on second maxilliped reduce to a lamina ( Fig. 5 L). Third maxilliped with 2 arthrobranches, ultimate segment about as long as penultimate segment ( Fig. 5 M). First pereiopod with an arthrobranch, pleurobranchs present on all pereiopods. Well-developed (with hooks on distal end) epipods present on third maxilliped and first 2 pereiopods, lacking on pereiopods 3–5.

Pereiopods. Chela and carpus of first pereiopod stouter and broader than chela and carpus of second pereiopod ( Fig. 6 A, B); chela of first pereiopod 1.86–2.12 (median 2.02) times as long as wide, 1.18–1.37 (median 1.22) times carpus length; tips of fingers rounded, without hook; dactylus 1.04–1.54 (median1.29) times as long as palm; carpus scarcely excavated distally 2.23–2.45 (median 2.36) times as long as wide, 1.12–1.30 (median 1.19) times length of merus. Merus 2.09–2.72 (median 2.29) times as long as wide, slightly shorter than ischium. Chela of second pereiopod 2.73–2.81 (median 2.79) times as long as wide, 0.74–0.78 (median 0.76) times as long as carpus; tips of fingers rounded, without hook, dactylus 1.27–1.55 (median 1.50) times as long as palm; carpus 5.21–6.67 (median 5.60) times as long as wide, 1.39–1.45 (median 1.43) times as long as merus; merus 4.33–4.84 (median 4.62) times as long as wide, scarcely shorter than ischium. Third pereiopod slender ( Fig. 6 C, E), not sexually dimorphic, dactylus 3.71–4.27 (median 4.05) times as long as wide (terminal claw and spines on flexor margin included), terminating in one large claw with 7–8 accessory spines on flexor margin; propodus 9.60–11.50 (median 10.45) times as long as wide, 3.00–3.43 (median 3.12) times as long as dactylus; carpus 5.00–5.63 (median 5.19) times as long as wide, 0.58–0.69 (median 0.63) times as long as propodus, 0.48–0.54 (median 0.51) times as long as merus; merus 7.40–8.38 (median 7.78) times as long as wide, 1.85–2.07 (median 1.97) times as long as carpus, bearing 3–4 small apressed movable spinules on posterior margin of outer surface. Ischium with a small spinule. Fifth pereiopod slender ( Fig. 6 D, F), dactylus 4.53–5.46 (median 4.72) times as long as wide (terminal claw and spines on flexor margin included), terminating in one large claw with 52–64 spinules on flexor margin, propodus 10.05–11.60 (median 11.06) times as long as wide, 2.38–2.48 (median 2.46) times length of dactylus, carpus 4.04– 5.00 (median 4.33) times as long as wide, 0.49–0.54 (median 0.52) times as long as propodus, 0.62–0.65 (median 0.64) times as long as merus; merus 5.87–7.65 (median 6.38) times as long as wide, 1.53–1.60 (median 1.57) times length of carpus, bearing 2–3 movable spinules on posterior margin of outer surface. Pleopods. Endopod of male first pleopod ( Fig. 6 H) elongated triangularly, long setae fringe along outer and distal margins medium long setae fringe along inner margin, 2.41–2.63 times as long as proximal width (n=2), 0.33 times as long as exopod, without appendix interna. Appendix masculina on male second pleopod ( Fig. 6 I) slender (5.64–6.25 times as long as distal wide), saccate, with some long spines on inner and numerous long spines on distal margins, appendix interna 0.81– 0.84 of appendix masculina.

Reproductive biology. Ovigerous females with few eggs; size of eggs (from one female with undeveloped and one with developed eggs) 0.96–1.10 x 0.68–0.74 mm.

Colouration. Semitransparent with tiny reddish dots on whole body, some scattered whitish blotches on carapace and similar coloured transversal bands on dorsal part of first to fifth abdominal segments. Faint reddish lines on posterior margin of first and anterior margin of third to fifth abdominal pleura.

Etymology. The new species is named after its type locality – Buton Island, Indonesia.

Remarks. Caridina butonensis n. sp. is close to C. opaensis in term of the morphology of the chelipeds, the pereiopods and the male sexual appendages. The new species can be distinguished from C. opaensis by its short and truncated rostrum lacking postorbital teeth (vs. rostrum slender, pointed, with 3–7 postorbital teeth in C. opaensis ), its small antennal spine fused with inferior orbital angle (vs. distinct, situated below inferior orbital angle in C. opaensis ), its relatively short penultimate segment of third maxilliped (penultimate as long as ultimate vs. penultimate longer than ultimate in C. opaensis ), no epipod on the third up to the fifth pereiopods (vs. reduced epipod on the third pereiopod in C. opaensis ), and its smaller size (2.18–3.79 mm carapace length vs. 3.06–4.54 mm carapace length in C. opaensis ). Caridina butonensis n. sp resembles also C. boehmei n. sp in cheliped morphology and reduced epipodial apparatus, however, it can be distinguished by the more reduced podobranch on the second maxilliped which becomes a lamina with some finger-like projections as in C. boehmei n. sp.. Further, the two species can easily be differentiated by the rostrum shape (distal conspicuous truncated vs. pointed in C. boehmei ) and the rostrum formula (0 + 3–9(4–7) / 1–8(3–6) vs. 0 + 0–2(0–1) / 0–2(0–1)). The truncated rostrum of C. butonensis n. sp. resembles of C. subventralis Richard & Clark 2005 described from Lake Bunyonyi, Uganda, East Africa. However, the new species differs by the epipodial formula (well developed epipods on pereiopods 1 and 2 vs. well developed epipods on pereiopod 1 to 4 in C. subventralis ), and the development of the podobranch on the second maxiliped (reduced to a lamella vs. well developed in C. subventralis ). Further, the distal margin of the telson is armed with 7–8 long spines (vs. 2–3 pairs of rather stout spines in C. subventralis ).

Distribution and habitat. Caridina butonensis n. sp. was found in small streams on Buton Island.

Figures

FIGURE 5. Caridina butonensis, n. sp., paratype female, cl 3.7 mm (ZMB 28094, Präp. Nr. 5031) (A) cephalothorax and cephalic appendages; (B) rostrum; paratypes (ZMB 28094) rostrum variability (C) ovig. female, cl 3.8 mm, (D) female, cl 3.1 mm; paratype female, cl 3.7 mm (ZMB 28094, Präp. Nr. 5031) (E) distal end of telson; (F) uropodal diaeresis; (G) scaphocerite; (H) mandible; (I) maxillula; (J) maxilla; (K) first maxilliped; (L) second maxilliped; (M) third maxilliped; (N) preanal carina.

FIGURE 6. Caridina butonensis, n. sp., paratype female, cl 3.7 mm (ZMB ZMB 28094, Präp. Nr. 5031) (A) first pereiopod; (B) second pereiopod; (C) third pereiopod; (D) fifth pereiopod; (E) dactylus of third pereiopod; (F) dactylus of fifth pereiopod; (G) endopod of female first pleopod; paratype male cl 3.1 mm ZMB 28094, Präp. Nr. 5030 (H) endopod of male first pleopod; (I) appendix masculina on male second pleopod.