Caridina serratirostris De Man, 1892

Figs 2A, 23

Caridina serratirostris De Man, 1892: 382, pl. 23, figs 28a–e (type locality: “Bangkalan” and “Bonea” Rivers, Selayar, Indonesia).

Caridina serratirostris var. typica Bouvier, 1925: 218 (partim), 480–486.

Caridina serratirostris – Roux 1926: 248. — Page et al. 2007: 647 (GenBank: DQ478515).

Not Caridina serratirostris – Holthuis 1978: 38; fig. 13.

Material examined

Paralectotypes (lectotype designated in Cai & Shokita 2006b) INDONESIA • 1 ♀ ovig., cl 4.0 mm, 1 ♂, cl 3.1 mm; Selayar Island, Bangkalan; 1889; M. Weber leg.; MNHN-IU-2015-1907 • 1 ♀ ovig., cl 4.1 mm; same collection data as for preceding; MNHN-IU-2015-1908 .

Other material

SOLOMON ISLANDS – Choiseul Island • 1 ♀ ovig., cl 5.0 mm; Vorama River; 06°58.687´S, 156°46.746´E; 15 m a.s.l.; 11 Oct. 2014; P. Gerbeaux, P. Keith and G. Marquet leg.; DNA voucher: CA1351; MNHN-IU-2018-2927 • 1 ♀ ovig., cl 3.4 mm; Lopakare River, upstream; 07°01.613´S, 156°46.567´E; 50 m a.s.l.; 20 Oct. 2014; P. Gerbeaux, P. Keith and G. Marquet leg.; MNHN-IU-2018-2928 • 1 ♀ ovig., cl 3.5 mm; Lopakare River, downstream; 07°01.834´S, 156°45.789´E; 21 Oct. 2014; 14 m a.s.l.; P. Gerbeaux, P. Keith and G. Marquet leg.; MNHN-IU-2018-2929 • 1 ♀ ovig., cl 3.6 mm; same collection data as for preceding; MNHN-IU-2018-2930 . – Kolombangara Island • 1 ♀ ovig., cl 3.6 mm; Vanga 2 River; 07°54.825´S, 156°57.7624´E; 18 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; DNA voucher: CA1523; MNHN-IU-2018-2931 . – Vella Lavella Island • 1 ♀ ovig., cl 3.8 mm; Vala Kadju; 07°49.860´S, 156°42.644´E; 28 Oct. 2016; P. Keith and C. Lord leg.; MNHN-IU-2018-2932 • 1 ♂, cl 2.5 mm; Maravari River; 07°51.703´S, 156°41.748´E; 31 Oct. 2016; P. Keith and C. Lord leg.; MNHN-IU-2018-2933 • 1 ♀ ovig., cl 3.6 mm; same collection data as for preceding; MNHN-IU-2018-2934 . – Isabel Island • 1 specimen; Rapa River; 07°28.527´S, 158°17.105´E; 0–7 m a.s.l.; 23 Oct. 2019; P. Keith, C. Lord, R. Causse and D. Boseto leg.; DNA voucher: CA2530; MNHN .

AUSTRALIA – Queensland • 1 ♀ ovig., cl 4.1 mm; Captain Cook Highway; 16°22.266´S, 145°24.551´E; 64 m a.s.l.; 14 Jun. 2016; B. Mos leg.; MNHN-IU-2018-2935 • 1 ♀ ovig., cl 3.2 mm; same collection data as for preceding; MNHN-IU-2018-2936 • 1 ♀ ovig., cl 3.8 mm; Johnstone River; 17°30.933´S, 145°59.437´E; 8 m a.s.l.; 11 Jun. 2016; B. Mos leg.; MNHN-IU-2018-2937 • 1 ♀ ovig., cl 3.2 mm; Barron River; 16°52.443´S, 145°40.830´E; 5 m a.s.l.; 8 Jun. 2016; B. Mos leg.; MNHN-IU-2018-2938 • 1 ♀ ovig., cl 3.6 mm; Mowbray River; 16°33.859´S, 145°27.844´E; 15 m a.s.l.; 14 Jun. 2016; B. Mos leg.; MNHN-IU-2018-2939 .

PAPUA NEW GUINEA • 1 ♀ ovig., cl 5.4 mm; New Britain, Rangihi swamp; 05°34.549´S, 149°28.943´E; 24 Oct. 2018; R. Causse, P. Keith and C. Lord leg.; MNHN-IU-2018-2940 .

Description

CEPHALOTHORAX. Antennal spine ventral to inferior orbital angle. Pterygostomian margin rounded. Rostrum (Fig. 23 m–n): straight, short, 0.6–0.9 of cl, reaching beyond end of antennular peduncle, armed with 22–26 teeth on dorsal margin, 7–10 of them situated on carapace behind orbital margin, ventral margin with 6–7 teeth. Eyes developed, anterior end reaching to 0.54 times length of basal segment of antennular peduncle. Long antennular peduncle, 0.78 (♀) – 0.95 (♂) times as long as carapace; second segment distinctly longer than third segment. Stylocerite reaching to middle of second segment of antennular peduncle.

PEREIOPODS. Epipods on first four pereiopods. P1 (Fig. 23a): chela about 2.3–2.9 times as long as wide, movable finger 4.1–5.1 times as long as wide, 1.1–1.8 times length of palm; carpus 3.3–4.5 times as long as wide. P2 (Fig. 23b) more slender and longer than first pereiopod, with chela 3.7–5.1 times as long as wide: movable finger 6.0–8.3 times as long as wide, 1.7–1.9 times length of palm; carpus slender, 8.3–10.9 times as long as wide. P3 (Fig. 23c): slender, dactylus (Fig. 23e) 3.7–4.4 times as long as wide (terminal spiniform seta included), with 6–7 spiniform setae on flexor margin including terminal one; propodus 14.2–17.1 times as long as wide, 4.1–5.3 times as long as dactylus, distinctive very long seta on distal end of carpus and merus. P5 (Fig. 23d): dactylus (Fig. 23f) 4.5–5.5 as long as wide, with 10–15 spiniform setae on flexor margin; propodus 18.7–24.0 times as long as wide, 4.5–5.5 times as long as dactylus.

ABDOMEN. Third abdominal somite with moderately convex dorsal profile. Sixth abdominal somite 0.56 times as long as carapace, 1.7 times as long as fifth somite, shorter than telson.

TELSON (Fig. 23i). 2.5–3.5 times as long as wide, with five pairs of dorsal spinules and pair of dorsolateral spinules; posterior margin with small median process, rounded, with 8–10 very long intermediate plumose setae longer than lateral ones.

MALE PLEOPODS. Pl1 (Fig. 23j): endopod rounded, 1.4 times as long as wide, reaching 0.22 times length of endopod, no appendix. Pl2 (Fig. 23k): appendix masculina reaching 0.77 times length of endopod; appendix interna reaching 0.75 times length of appendix masculina.

PRE- ANAL CARINA (Fig. 23g). High, with a spine.

UROPODAL DIAERESIS (Fig. 23h). With 15–17 spinules.

EGGS. Ovigerous females with small eggs, size: 0.30–0.38 × 0.18–0.23mm.

Habitat

Caridina serratirostris lives from the estuarine brackish water to the fresh water in the lower course of the rivers.

Colour pattern (Fig. 26D)

The body is yellowish to reddish with many red dots.

Distribution

This species occurs in Indonesia (Selajar), the Solomon Islands, Australia and Papua New Guinea (New Britain).

Remarks

Our specimens fit well with the types from Selayar: straight rostrum, 0.6–0.9 of cl (vs 0.6–0.9 in the type specimens), sometimes reaching the end of the antennular peduncle, armed with 22–26 teeth on dorsal margin (vs 20–27), 7–10 of them situated on carapace behind orbital margin (vs 8–9), ventral margin with 6–7 teeth (vs 4–7); P1 carpus 3.3–4.5 times as long as wide (vs 3.1–4.9); P2 carpus 8.3–10.9 times as long as wide (vs 7.0–9.0); P3 dactylus with 6–7 spiniform setae (vs 6–7) propodus 4.1–5.3 times as long as dactylus (vs 3.8–4.2); uropodal diaresis with 15–17 spinules (vs 14–19); small eggs, 0.30–0.38 × 0.18–0.23 mm (vs 0.28–0.31 × 0.13–0.15); no appendix interna on the endopod of the male first pleopod.