Caridina gracilirostris De Man, 1892

Mazancourt, Valentin de, Boseto, David, Marquet, Gerard & Keith, Philippe, 2020, Solomon’s Gold Mine: Description or redescription of 24 species of Caridina (Crustacea: Decapoda: Atyidae) freshwater shrimps from the Solomon Islands, including 11 new species, European Journal of Taxonomy 696, pp. 1-86 : 12-14

publication ID	https://doi.org/ 10.5852/ejt.2020.696
publication LSID	lsid:zoobank.org:pub:265EDD08-7AA8-4835-B7F6-353E7992633E
DOI	https://doi.org/10.5281/zenodo.4336310
persistent identifier	https://treatment.plazi.org/id/03D487FE-6B60-5558-FDFE-77FFFE488069
treatment provided by	Valdenar
scientific name	Caridina gracilirostris De Man, 1892
status

Treatment

Caridina gracilirostris De Man, 1892 View in CoL

Figs 2E View Fig , 4 View Fig , 25A View Fig

Caridina gracilirostris De Man, 1892: 399 View in CoL , pl. 25: fig. 31a–d (type locality: several localities, Sulawesi (Celebes) Indonesia).

Caridina gracilirostris View in CoL – Bouvier 1925: 142, figs 305–307. — Blanco 1935: 32, pl. 2, figs 11–17. — de Mazancourt et al. 2019a: 166, 169–170.

Material examined

Paralectotypes (lectotype designated by Cai & Ng 2007) INDONESIA • 2 ♂♂, cl 3.5–3.7 mm, 1 ♀ ovig., cl 5.1 mm; Sulawesi, Balangnipa ; Oct.–Nov. 1888; M. Weber leg.; MNHN-IU-2015-1737 .

Other material

SOLOMON ISLANDS – Kolombangara Island • 1 ♂, cl 3.0 mm; Jack Harbour River ; 08°03.085´S, 157°10.945´E; 11 m a.s.l.; 11 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; DNA voucher: CA1497; MNHN-IU-2018-2804 . GoogleMaps – Isabel Island • 1 specimen; Kolopakissa, Zari River ; 07°36.314´S, 158°40.103´E; ca 0–5 m a.s.l.; 26 Oct. 2019; P. Keith, C. Lord, R. Causse and D. Boseto leg.; DNA voucher: CA2506; MNHN GoogleMaps .

AUSTRALIA • 1 ♂, cl 4.2 mm; Queensland, Johnstone River ; 17°30.456´S, 145°59.525´E; 7 m a.s.l; 11 Jun. 2016; B. Mos leg.; DNA: CA1677; MNHN-IU-2018-2805 GoogleMaps • 1 ♀ ovig., cl 5.6 mm; Queensland, Mulgrave River ; 17°08.841´S, 145°52.786´E; 10 m a.s.l.; 7 Jun. 2016; B. Mos leg.; DNA voucher: CA1681; MNHN-IU-2018-2806 GoogleMaps • 1 ♂, cl 4.2 mm; same collection data as for preceding; MNHN-IU-2018-2807 GoogleMaps .

Description

CEPHALOTHORAX. Antennal spine short, situated below inferior orbital angle. Pterygostomian margin subrectangular. Rostrum ( Fig. 4m View Fig ): strongly upturned, very long, 1.3–2.6 of cl, reaching far beyond distal end of scaphocerite, armed with 5–9 teeth on dorsal margin, with 1–2 apical teeth, 0–1 of them situated on carapace behind orbital margin, ventral margin with 21–35 teeth. Eyes well developed, anterior end reaching to 0.54–0.87 length of basal segment of antennular peduncle. Antennular peduncle 0.70 (♀) – 0.93 (♂) times as long as carapace. Anterolateral angle pointed, reaching to 0.40 length of second segment, second segment distinctly longer than third segment. Stylocerite reaching to 0.72–0.80 length of basal segment of antennular peduncle.

PEREIOPODS. Epipods on first four pereiopods. P1 ( Fig. 4a View Fig ): chela about 1.9–2.9 times as long as wide, movable finger 2.8–4.0 times as long as wide, 0.7–1.3 times length of palm; carpus 1.5–1.9 times as long as wide. P2 ( Fig. 4b View Fig ) more slender and longer than first pereiopod, with chela 2.0–2.5 times as long as wide: movable finger 3.3–4.2 times as long as wide, 1.1–1.8 times length of palm; carpus slender, 3.2–5.1 times as long as wide. P3 ( Fig. 4c View Fig ): dactylus stout ( Fig. 4e View Fig ), 3.3–3.8 times as long as wide (terminal spiniform seta included), with 7–10 spiniform setae on flexor margin in addition to terminal one; propodus 11.7–14.0 times as long as wide, 3.6–4.5 times as long as dactylus. P5 ( Fig. 4d View Fig ): dactylus ( Fig. 4f View Fig ) 4.0–4.4 as long as wide, with 26–33 spiniform setae on flexor margin; propodus 14.9–22.4 times as long as wide, 3.8–4.4 times as long as dactylus.

ABDOMEN. Third abdominal somite with moderarely convex dorsal profile. Sixth abdominal somite 0.8 times as long as carapace, 2.0 times as long as fifth somite, as long as telson.

TELSON ( Fig. 4i View Fig ). Very slender, 4.5 times as long as wide, with four pairs of dorsal spinules and one pair of dorsolateral spinules; posterior margin without a median process; distal setae very stout, lateral pair distinctly longer than intermediate setae (mostly one pair).

MALE PLEOPODS. Pl1 ( Fig. 4j View Fig ): endopod subtriangular, 2.1 times as long as wide, 0.21 times as long as exopod, without appendix interna. Pl2 ( Fig. 4k View Fig ): appendix masculina reaching 0.50 times length of endopod; appendix interna reaching 0.50 of appendix masculina.

PRE- ANAL CARINA ( Fig. 4g View Fig ). With spine.

UROPODAL DIAERESIS ( Fig. 4h View Fig ). With 6–10 spinules.

EGGS ( Fig. 4l View Fig ). Size: 0.34–0.43 × 0.19–0. 26 mm.

Habitat

In the lower course of streams under marine influence, very often in brackish water.

Colour pattern ( Fig. 25A View Fig )

Totally translucent body with a rostrum alternating black and red areas.

Distribution

Widely distributed in the tropical and subtropical Indo-Pacific region: Indonesia, the Philippines, India, Australia and the Solomon Islands.

Remarks

Our specimens fit well with the description given by Cai & Ng (2007): rostrum very long, reaching far beyond distal end of scaphocerite, strongly upturned, with presence of 0–1 postorbital teeth (vs 0 in Cai & Ng (2007)), 5–9 dorsal teeth (vs 3–9) and 21–35 ventral teeth (vs 28–36); P1 carpus 1.5–1.9 times as long as wide (vs 1.7); P2 carpus 3.2–5.1 times as long as wide (vs 4). P3 dactylus with 7–10 spiniform setae (vs 8), propodus 3.6–4.5 times as long as dactylus (vs 4.0); P5 dactylus with about 26–33 spiniform setae (vs 37) and propodus 3.8–4.4 times as long as dactylus (vs 3.8); uropodal diaeresis 6–10 (vs 5–11); small eggs 0.32–0.43 × 0.19–0.26 mm (vs 0.40 × 0.25 mm); no appendix interna on the endopod of the male first pleopod.