Caridina gracilirostris De Man 1892
Creators: name: Mazancourt, Valentin de
name: Boseto, David
name: Marquet, Gerard
name: Keith, Philippe
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Atyidae
Caridina
Caridina gracilirostris

description: Caridina gracilirostris De Man, 1892
Figs 2E, 4, 25A
Caridina gracilirostris De Man, 1892: 399, pl. 25: fig. 31a–d (type locality: several localities, Sulawesi (Celebes) Indonesia).
Caridina gracilirostris – 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. – 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.
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 • 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 • 1 ♂, cl 4.2 mm; same collection data as for preceding; MNHN-IU-2018-2807.
Description
CEPHALOTHORAX. Antennal spine short, situated below inferior orbital angle. Pterygostomian margin subrectangular. Rostrum (Fig. 4m): 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): 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) 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): dactylus stout (Fig. 4e), 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): dactylus (Fig. 4f) 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). 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): endopod subtriangular, 2.1 times as long as wide, 0.21 times as long as exopod, without appendix interna. Pl2 (Fig. 4k): appendix masculina reaching 0.50 times length of endopod; appendix interna reaching 0.50 of appendix masculina.
PRE- ANAL CARINA (Fig. 4g). With spine.
UROPODAL DIAERESIS (Fig. 4h). With 6–10 spinules.
EGGS (Fig. 4l). 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)
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.
description: Published as part of 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, pp. 1-86 in European Journal of Taxonomy 696 on pages 12-14, DOI: 10.5852/ejt.2020.696, http://zenodo.org/record/3973435