Caridina marquesensis, Mazancourt & Marquet & Keith, 2019

Mazancourt, Valentin de, Marquet, Gérard & Keith, Philippe, 2019, Revision of freshwater shrimps belonging to Caridina weberi complex (Crustacea: Decapoda: Atyidae) from Polynesia with discussion on their biogeography, Journal of Natural History 53 (13), pp. 815-847 : 825-828

Caridina marquesensis n. sp.

www.zoobank.org/ urn:lsid:zoobank.org:act:F518C8E2-A785-42B7-A455-0CE2CA2CE508 ( Figure 4 )

Caridina weberi – Edmondson 1935: 10 , Figure 4 (h); Adamson 1935: 16, 1939: 36; Marquet 1988 (partim); Marquet 1991: 129 – 130 (partim); Poupin 1998: 9 (partim); Keith and Vigneux 2002: 126 (partim), photo 7 & 8; Keith et al. 2002: 44 – 45 (partim); Keith et al. 2013: 84 – 85 (partim).

Material examined

Type material. Holotype: 1 ♂, cl 2.9 mm, 9 October 2017, 09°49.750 ′ S 135°04.418 ′ W, Ta ’ ooa river, Hiva Oa Island, French Polynesia, altitude 220m, G. Marquet, P. Tiberghien, E. Feunteun, P. Gerbeaux & M. Gerbeaux coll., MNHN-IU- 2017-66.

Paratypes: 1 ♀ ovig, cl 3.3 mm, same data as holotype, MNHN-IU- 2017-67 (DNA: CA2067 ); 1 ♀, cl 2.8 mm, same data as holotype, MNHN-IU- 2017-68 (DNA: CA2066 ); 1 ♀ ovig, cl 4.7 mm, 18 October 2017, 08°51.126 ′ S 140°06.066 ′ W, Taipivai river , Nuku Hiva Island, French Polynesia, altitude 130m, G. Marquet, P. Tiberghien, P. Keith & H. Lucien- Brun coll., MNHN-IU- 2017-69 (DNA: CA2075 ); 1 ♀ ovig, cl 4.8mm, same data as previous, MNHN-IU- 2017-70 (DNA: CA2074 ); 1 ♀, cl 3.2 mm, 14 October 2017, 09°25.452 ′ S 140° 03.409 ′ W, unnamed rivulet, Ua Pou Island , French Polynesia, altitude 130m, G. Marquet, P. Tiberghien, P. Keith & H. Lucien-Brun coll., MNHN-IU- 2017-71 (DNA: CA2071 ); 1 ♀, cl 3.4 mm, same data as previous, MNHN-IU-2018-257 (DNA: CA2070 ); 1 ♀ ovig, cl 5.2 mm, 21 February 2000, 09°24.180 ′ S 140°03.060 ′ W, Paaumea river , Ua Pou Island, French Polynesia, altitude 200m, P. Keith & E. Vigneux coll., MNHN-IU-2018-258; 1 ♀, cl 4.6 mm, same data as previous, MNHN-IU-2018-259 .

Comparative material. Type material

Caridina weberi De Man, 1892 .

Syntypes: 2 ♂, cl 4.4 – 4.5 mm and 1 ♀ ovig, cl 6.1 mm, Kotting , Flores Island, Indonesia, M. Weber coll., MNHN-IU-2015 – 1755.

Description

Cephalothorax. Rostrum ( Figure 4 (h)): always bent down, short, 0.3 – 0.4 of cl, reaching to base or middle of second segment of antennular peduncle, armed dorsally with 10 – 13 teeth, 0 – 3 teeth on carapace posterior to orbital margin (mostly 2 – 3), ventral margin with 0 – 3 teeth. Rostral formula (0 – 3) 10 – 13/0 – 3. Suborbital angle indistinguishably fused with antennular tooth. Pterygostomian margin rectangularly rounded.

Eyes well developed, anterior end reaching to 0.62 length of antennular peduncle basal segment. Antennular peduncle 0.50 times as long as carapace. Anterolateral angle reaching 0.20 length of second segment, second segment subequal to third. Stylocerite reaching to 0.9 length of antennular peduncle basal segment. Scaphocerite reaches just slightly beyond tip of antennular peduncle, about 2.1 times longer than wide.

Mouthparts. Left mandible, right mandible, first maxilla, second maxilla, first maxilliped, second maxilliped and third maxilliped typical of genus.

Pereiopods. Epipods on first four pereiopods.

Pereiopod 1 ( Figure 4 (a)): chela about 2.0 – 2.2 times as long as wide, movable finger 2.2 – 3.1 times as long as wide, 0.6 – 0.9 times length of palm, carpus 1.3 – 1.7 times as long as wide. Tips of both fingers with prominent claws ( Figure 4 (b)).

Pereiopod 2 ( Figure 4 (c)) more slender and long than the first pereiopod with chela 2.5 – 3.3 times as long as wide: movable finger 4.2 – 5.2 times as long as wide, 1.5 – 1.8 times length of palm, carpus slender 5.5 – 6.6 times as long as wide.

Pereiopod 3 ( Figure 4 (d, g)): stout, dactylus 2.7 – 3.1 times as long as wide including terminal spine) with 6 – 7 spines including terminal spine, propodus with numerous spines on ventral margin, 8.0 – 9.3 times as long as wide, 3.4 – 4.3 times as long as dactylus.

Pereiopod 5 ( Figure 4 (e, f)): dactylus 3.4 – 5.5 as long as wide, ending in two large claws with 32 – 55 spiniform setae on flexor margin, propodus 13.0 – 17.7 times as long as wide, 3.8 – 5.2 times as long as dactylus.

Abdomen. Third abdominal somite with moderately convex dorsal profile. Sixth abdominal somite about 0.37 of carapace, 0.7 times as long as fifth somite, shorter than telson. Telson ( Figure 4 (l)) 2.1 times as long as wide, with four to six pairs of dorsal spines and one pair of dorsolateral spines, posterior margin with a median process, rounded with 6 – 14 intermediate plumose setae longer than lateral spines.

First male pleopod ( Figure 4 (m)): Endopod extending to half length of exopod, elongate, with a developed appendix interna near distal end of endopod.

Second male pleopod ( Figure 4 (n)): Appendix masculina reaching 0.72 times length of endopod, appendix interna reaching about 0.50 times appendix masculina length.

Preanal carina ( Figure 4 (i)): High, unarmed.

Uropodal diaeresis ( Figure 4 (k)): with 16 – 22 spinules.

Eggs ( Figure 4 (j)): Size 0.39 – 0.47 × 0.23 – 0. 27mm.

Habitat

This new species prefers fresh and well-oxygenated running waters from the lower course to the higher course. In Nuku Hiva (Marquesas islands) C. marquesensis n. sp. lives in lentic habitat of the lower course, associated with accumulations of leaves, where it collects small detritus and eventually is able to swim ( Fossati et al. 2002).

Etymology

This new species is named marquesensis , from the name of the archipelago, Marquesas Islands, where it occurs.

Colour pattern ( Figure 7 (c))

The live general colour of the body is bluish to greenish and slightly translucent. Numerous red spots are visible all over the body.

Distribution ( Figure 8 )

This species is known only from Marquesas islands (Nuku Hiva, Hiva Oa, Ua Pou Islands) so far and seems to be endemic.

Remarks

This new species was identified as C. weberi several times: Edmondson 1935, Adamson (1935, 1939), Marquet (1988), Marquet (1991), Poupin (1998), Keith and Vigneux (2002), Keith et al. (2002), Keith et al. (2013). Indeed, this species looks like C. weberi sensu stricto by its straight or bent down rostrum, 0.3 – 0.4 of cl, (vs 0.4 in C. weberi ) reaching to the base or middle of second segment of antennular peduncle with numerous dorsal teeth 10 – 13 (vs 10 – 19 in C. weberi ), but differs by the presence of 0 – 3 dorsal teeth situated on carapace behind orbital margin (vs 0 in C. weberi ). Also its P1 movable finger is shorter 0.6 – 0.9 times length of palm (vs 1.2 – 1.3 in C. weberi ) as is its P1 carpus 1.3 – 1.7 times as long as wide (vs 1.9 – 2.0 in C. weberi ), and its P2 carpus is longer, 5.5 – 6.6 times as long as wide (vs 4.9 – 5.0 in C. weberi ). Furthermore, the posterior margin of the telson always shows only one pair of lateral spines (vs 2 in C. weberi ).

This species differs from C. tupaia n. sp. by its rostrum with mostly 2 – 3 teeth on carapace posterior to orbital margin (vs mostly 0 in C. tupaia n. sp.), its tips of both P1 fingers with prominent claws (vs not in C. tupaia n. sp.) and its P5 dactylus ending in two large claws (vs one claw in C. tupaia n. sp.).

Figures

Figure 4. Caridina marquesensis n. sp. Paratype (MNHN-IU-2017–71; DNA: CA2071), (a). first pereiopod; (b). first pereiopod detail of the fingertips; (c). second pereiopod; (d). third pereiopod; (c). fifth pereiopod; (f). dactylus of fifth pereiopod; (g). dactylus of third pereiopod; h. cephalothorax; (i). preanal carina; (k). uropodal diaeresis; (l). telson. Paratype (MNHN-IU-2017-69; DNA: CA2075), j. eggs. Holotype (MNHN-IU-2017-66), m. first pleopod; n. second pleopod.

Figure 7. Live colouration of the species: (a, b). C. tupaia n. sp. (c). C. marquesensis n. sp. (d, e). C. rapaensis. (f). C. futunensis n. sp. (g). Habitat of C. futunensis n. sp. in Futuna. Credits: (a, b, c): G. Marquet; (d, e): E. Vigneux; (f): V. de Mazancourt; (g): A. Dutartre.

Figure 8. Distribution map of the four species studied with oceanic currents of Southern Polynesia (from Martinez et al. 2009) represented: SEC. South Equatorial Current. SECC. South Equatorial Countercurrent. MCC. Marquesas Countercurrent. STCC. South Tropical Countercurrent. GYRE. South Pacific Gyre.