Caridina piokerai, 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 : 57-59

Caridina piokerai sp. nov.

urn:lsid:zoobank.org:act:CF802FC0-547B-4E48-A7D5-9E99A4561F9D

Figs 2U , 18

Caridina cf. weberi sp. 5 – de Mazancourt et al. 2019a: 166 , 169–170.

Etymology

This species is dedicated to Piokera S. Holland (Ecological Solutions Solomon Islands team member) who helped with the sampling in Kolombangara Island.

Material examined

Holotype

SOLOMON ISLANDS • ♀, cl 3.5mm; Kolombangara Island, Poitete River; 07°53.077´S, 157°07.776´E; 13 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; DNA voucher: CA1909; MNHN-IU-2018-2896 .

Paratypes

SOLOMON ISLANDS – Kolombangara Island • 1 ♀ ovig., cl 2.9 mm; Vagé River ; 08°06.640´S, 157°00.1674´E; 59 m a.s.l.; 10 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; MNHN-IU-2018-2897 • 1 ♀ ovig., cl 3.1 mm; same collection data as for preceding; MNHN-IU-2018-2898 • 1 ♀ ovig., cl 3.3 mm; same collection data as for preceding; MNHN-IU-2018-2899 • 1 ♀ ovig., cl 2.9 mm; Liva River ; 08°03.881´S, 157°10.421´E; 11 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; MNHN-IU-2018-2900 • 1 ♀ ovig., cl 3.6 mm; Sulumuni River ; 08°02.253´S, 157°09.257´E; 148 m a.s.l.; 12 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; MNHN-IU-2018-2901 • 1 ♀ ovig., cl 3.3 mm; Vanga 1 River ; 07°55.088´S, 156°57.624´E; 18 Nov. 2015; P. Keith, C. Lord and G. Marquet leg.; MNHN-IU-2018-2902 . – Choiseul Island • 1 ♀ ovig., cl 3.1 mm; Lopakare River ; MNHN-IU-2018-2903 • 1 ♀, cl 3.9 mm; 07°01.613´S, 156°46.567´E; 50 m a.s.l.; 20 Oct. 2014; P. Gerbeaux, P. Keith and G. Marquet leg.; DNA voucher: CA1930; MNHN-IU-2018-2904 . – Vella Lavella Island • 1 ♀ ovig., cl 2.6 mm; Vala Kadju River ; MNHN-IU-2018-2905 • 1 ♀ ovig., cl 2.8 mm; 07°49.860´S, 156°42.644´E; 17 m a.s.l.; 28 Oct. 2016; P. Keith and C. Lord leg.; MNHN-IU-2019-125 • 1 ♀, cl 3.2 mm; Maravari River ; 07°51.703´S, 156°41.768´E; 81 m a.s.l.; 31 Oct. 2016; P. Keith and C. Lord leg.; MNHN-IU-2018-2907 • 1 ♀ ovig., cl 2.8 mm; same collection data as for preceding; MNHN-IU-2018-2908 • 1 ♀ ovig., cl 3.2 mm; same collection data as for preceding; MNHN-IU-2018-2909 • 1 ♀ ovig., cl 3.2 mm; same collection data as for preceding; MNHN-IU-2018-2910 • 1 ♀ ovig., cl 2.1 mm; same collection data as for preceding; DNA voucher: CA1981; MNHN-IU-2018-2911 .

Description

CEPHALOTHORAX. Suborbital angle indistinguishably fused with antennal spine. Pterygostomian margin rounded. Rostrum ( Fig. 18k ): straight or bent down, short, 0.3–0.5 of cl, reaching to second segment of antennular peduncle, armed with 9–13 teeth on dorsal margin, 0–1 of them situated on carapace behind orbital margin, ventral margin with 1–4 teeth. Eyes well developed, anterior end reaching to 0.66 length of basal segment of antennular peduncle. Antennular peduncle 0.50 times as long as carapace. Anterolateral angle reaching 0.33 length of second segment, second segment shorter than third segment. Stylocerite reaching to 0.90 length of basal segment of antennular peduncle.

PEREIOPODS. Epipods on first four pereiopods. P1 ( Fig. 18a ): chela about 1.9–2.3 times as long as wide, movable finger 2.5–3.6 times as long as wide, 0.9–1.5 times length of palm; carpus 1.4–1.8 times as long as wide. P2 ( Fig. 18b ) more slender and longer than first pereiopod, with chela 2.4–3.0 times as long as wide: movable finger 3.9–5.2 times as long as wide, 1.4–2.1 times length of palm; carpus slender, 4.6–6.2 times as long as wide. P3 ( Fig. 18c ): stout, dactylus ( Fig. 18e ) 2.6–3.4 times as long as wide (terminal spiniform seta included), with 4–5 spiniform setae on flexor margin in addition to terminal one; propodus 8.1–10.4 times as long as wide, 3.9–5.3 times as long as dactylus. P5 ( Fig. 18d ): dactylus ( Fig. 18f ) 2.7–4.5 times as long as wide, with 21–33 spiniform setae on flexor margin; propodus 10.5– 15.0 times as long as wide, 3.5–6.2 times as long as dactylus.

ABDOMEN. Third abdominal somite with moderately convex dorsal profile. Sixth abdominal somite 0.48 times as long as carapace, 1.4 times as long as fifth somite, 0.88 as long as telson.

TELSON ( Fig. 18i ). 3 times as long as wide, with five pairs of dorsal spinules and pair of dorsolateral spinules; posterior margin with median process, rounded, with 5–10 very long intermediate setae longer than lateral ones.

MALE PLEOPODS. No males.

PRE- ANAL CARINA ( Fig. 18g ). High, unarmed.

UROPODAL DIAERESIS ( Fig. 18h ). With 17–20 spinules.

EGGS. Size: 0.39–0.47 × 0.20–0.28 mm.

Habitat

This species is largely rheophile and prefers fresh and well-oxygenated waters from the lower course to the higher course of rivers (17–148m a.s.l.).

Colour pattern

Unknown.

Distribution

This new species occurs on several of the Solomon Islands (Choiseul, Kolombangara and Vella Lavella).

Remarks

These specimens from the Solomon Islands are very similar to C. macrodentata Cai & Shokita (2006a) because of the large teeth on the dorsal margin of the rostrum. However, the P1 and P2 carpus are slender, 1.4–1.8 times as long as wide (vs 1.2 in C. macrodentata ) and 4.6–6.2 (vs 3.8), respectively, and the P5 dactylus is longer, 3.5–6.2 as long as wide (vs 2.4), not ending in two large claws (vs ending in two large claws).

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. 18. Caridina piokerai 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-2018-2900 (a–k).