Caridina poarae, Mazancourt & Boseto & Marquet & Keith, 2020

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 : 64-65

Caridina poarae sp. nov.

urn:lsid:zoobank.org:act:CF9FB7DB-335A-4A29-ABD4-68082519CEFF

Figs 2R , 21

Etymology

This new species is named after the local name of the type locality, river Poarae. The name is used as an apposition.

Material examined

Holotype

SOLOMON ISLANDS • ♀, cl 4.1 mm; Ranongga Island , Poarae River; 08°05.028´S, 156°35.979´E; 25 Oct. 2016; D. Boseto leg.; DNA voucher: CA2350; MNHN-IU- 2018-2920.

Paratypes

SOLOMON ISLANDS • 1 juvenile, cl 2.9 mm; same collection data as for holotype; DNA voucher: CA2348; MNHN-IU- 2018-2921 • 1 ♀ ovig., cl 3.4 mm; same collection data as for holotype; DNA voucher: CA2349; MNHN-IU- 2018-2922 .

Other material

VANUATU • 1 ♀ ovig., cl 5.3 mm; Santo Island ; MNHN-IU- 2018-2923 • 1 ♀, cl 5.3 mm; same collection data as for preceding; MNHN-IU- 2018-2924 .

Description

CEPHALOTHORAX. Suborbital angle indistinguishably fused with antennal spine. Pterygostomian margin broadly subrectangular. Rostrum ( Fig. 21k ): straight, short, 0.3 of cl, reaching to near end of first segment of antennular peduncle, unarmed dorsally, ventral margin with 1–3 teeth. Eyes well developed. Antennular peduncle 0.54 times as long as carapace. Anterolateral angle reaching 0.33 length of second segment, second segment little longer than third segment. Stylocerite reaching to 0.83 times length of basal segment of antennular peduncle.

PEREIOPODS. Epipods on first four pereiopods. P1 ( Fig. 21a ): chela about 2.0–2.3 times as long as wide, movable finger 2.3–3.2 times as long as wide, 0.8–1.2 times length of palm; carpus 1.3–1.7 times as long as wide. P2 ( Fig. 21b ) more slender and longer than first pereiopod, with chela 1.4–3.8 times as long as wide: movable finger 4.7–4.9 times as long as wide, 1.4–1.6 times length of palm; carpus slender, 4.5–5.7 times as long as wide. P3 ( Fig. 21c ): stout, dactylus ( Fig. 21e ) 2.9–3.0 times as long as wide (terminal spiniform seta included), with 5–6 spiniform setae on flexor margin including terminal; propodus 6.7–7.7 times as long as wide, 3.2–3.7 times as long as dactylus. P5 ( Fig. 21d ): dactylus ( Fig. 21f ) 3.9–4.5 times as long as wide, with 42–61 spiniform setae on flexor margin; propodus 9.6– 13.8 times as long as wide, 2.9–3.5 times as long as dactylus.

ABDOMEN. Third abdominal somite with moderately convex dorsal profile. Sixth abdominal somite 0.48 times as long as carapace, 1.5 times as long as fifth somite, shorter than telson.

TELSON ( Fig. 21i ). 2.7 times as long as wide, with four or five pairs of dorsal spinules and pair of dorsolateral spinules, posterior margin with median process, rounded, with 5–8 plumose intermediate setae longer than lateral ones.

MALE PLEOPODS. No males.

PRE- ANAL CARINA ( Fig. 21g ). High, unarmed.

UROPODAL DIAERESIS ( Fig. 21h ). With 19–24 spinules.

EGGS. Ovigerous females with eggs size: 0.42–0.49 × 0.22–0.32 mm.

Habitat

This new species is rheophile and prefers fresh and well-oxygenated waters from the middle to upper course of rivers.

Colour pattern

Unknown.

Distribution

This species occurs in Solomon Islands (Ranongga) and Vanuatu (Santo).

Remarks

This new species looks like C. typus by its unarmed dorsal rostrum, but it is distinguished by its shorter P3 propodus, 6.7–7.7 times as long as wide (vs 7.9–10.0 in C. typus), and P3 propodus 3.2–3.7 times as long as dactylus, (vs 3.6–4.6). This new species also looks like C. jeani , by its unarmed dorsal rostrum but it is easily distinguish by its longer P3 dactylus, 4.4–4.6 times as long as wide (vs 1.6 in C. jeani ) and its P5 dactylus, 3.9–4.5 times as long as wide (vs 2.7–3.2).

Figures

Fig. 2. Bayesian inference phylogenetic tree of the species studied. Numbers above branches are Bayesian posterior probabilities, numbers under branches are Maximum Likelihood bootstrap values. Results of the three species delimitation methods are indicated by the black bars on the right of the tree. Each bar represents a species recognized by the analysis.

Fig. 21. Caridina poarae sp. nov. a. First pereiopod. b. Second pereiopod. c. Third pereiopod. d. Fifth pereiopod. e. Dactylus of third pereiopod. f. Dactylus of fifth pereiopod. g. Pre-anal carina. h. Uropodal diaeresis. i. Telson. j. Eggs. k. Cephalothorax. MNHN-IU-2018-2922 (a–k).