Caridina weberi 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 : 49-52

Caridina weberi De Man, 1892

Figs 2T , 15 , 26C

Caridina weberi De Man, 1892: 371 , pl. 22, fig. 23a (type locality: Kotting, Flores, Indonesia).

Caridina weberi – Bouvier 1925: 242, figs. 562–571. — Roux 1928: 203–204. — Cai & Ng 2001: 666, fig. 3.

Caridina cf. weberi sp. 2 – de Mazancourt et al. 2019a: 166 , 169–170.

Not Caridina weberi Edmondson, 1935: 8 ; figs 3a–f.

Material examined

Syntypes

INDONESIA • 2 ♂♂, cl 4.4–4.5 mm, 1 ♀ ovig., cl 6.1 mm; Flores Island , Kotting; Dec. 1888; M. Weber leg.; MNHN-IU-2015-1755 .

Other material

SOLOMON ISLANDS – Kolombangara Island • 1 ♀ ovig., cl 6.4 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.; DNA voucher:

CA1516; MNHN-IU- 2018-2867. – Malaita Island • 1 ♂, cl 3.5 mm; Tanana River; 09°17.383´S, 167°07.012´E; 276 m a.s.l.; 16 Jun. 2015; D. Boseto leg.; DNA voucher: CA1511; MNHN-IU- 2018-2868 • 1 ♂, cl 3.7 mm; same collection data as for preceding; MNHN-IU- 2018-2869 • 1 ♂, cl 3.8 mm; same collection data as for preceding; MNHN-IU- 2018-2870 .

PAPUA NEW GUINEA – New Britain • 1 ♂, cl 4.6 mm; Bereme village, Huvenganga River ; 05°45.187´S, 150°35.0014´E; 19 Oct. 2018; R. Causse, P. Keith and C. Lord leg.; MNHN-IU- 2018-2871 • 1 ♂, cl 5.3 mm; same collection data as for preceding; MNHN-IU- 2018-2872 • 1 ♀ ovig., cl 6.8 mm; same collection data as for preceding; MNHN-IU- 2018-2873 • 1 ♀ ovig., cl 7.5 mm; same collection data as for preceding; DNA voucher: CA2254; MNHN-IU- 2018-2874 • 1 ♀ ovig., cl 6.2 mm; Bereme district, Galaku River ; 05°45.187´S, 150°35.0014´E; 20 Oct. 2018; R. Causse, P. Keith and C. Lord leg.; MNHN-IU- 2018-2875 • 1 ♀ ovig., cl 6.5 mm; Bereme district, Wogan River ; 05°45.187´S, 150°35.0014´E; 21 Oct. 2018; R. Causse, P. Keith and C. Lord leg.; DNA voucher: CA2244; MNHN- IU- 2018-2876 .

Description

CEPHALOTHORAX. Suborbital angle indistinguishably fused with antennal spine. Pterygostomian margin rounded. Rostrum ( Fig. 15m ): straight, short, 0.4 of cl, reaching to base or near middle of second segment of antennular peduncle, armed with 11–23 teeth on dorsal margin, 0–2 of them situated on carapace behind orbital margin, ventral margin with 2–5 teeth. Eyes well developed, anterior end reaching to 0.7 times length of basal segment of antennular peduncle. Antennular peduncle 0.64 times as long as carapace. Anterolateral angle reaching 0.21 length of second segment, second segment longer than third segment. Stylocerite reaching to 0.75 length of basal segment of antennular peduncle.

PEREIOPODS. Epipods on first four pereiopods. P1 ( Fig. 15a ): chela about 2.0–2.3 times as long as wide, movable finger 2.6–4.1 times as long as wide, 0.8–1.5 times length of palm; carpus 1.4–2.0 times as long as wide. P2 ( Fig. 15b ) more slender and longer than first pereiopod, with chela 2.5–2.9 times as long as wide: movable finger 3.9–5.1 times as long as wide, 1.3–1.7 times length of palm; carpus slender, 4.8–5.5 times as long as wide. P3 ( Fig. 15c ): stout, dactylus ( Fig. 15e ) 2.8–37 times as long as wide (terminal spiniform seta included), with 6–8 spiniform setae on flexor margin in addition to terminal one; propodus 9.5–12.7 times as long as wide, 4.0–4.6 times as long as dactylus. P5 ( Fig. 15d ): dactylus ( Fig. 15f ) 3.9–5.2 times as long as wide, with 47–66 spiniform setae on flexor margin; propodus 13.3– 19.3 times as long as wide, 3.8–4.5 times as long as dactylus.

ABDOMEN. Third abdominal somite with moderately convex dorsal profile. Sixth abdominal somite about half length of carapace, 1.7 times as long as fifth somite, reaching 0.84 times length of telson.

TELSON ( Fig. 15i ). 2.6 times as long as wide, with five to seven pairs of dorsal spinules and one pair of dorsolateral spinules; posterior margin with median process, rounded, with 6–11 very long intermediate setae longer than one or two lateral ones.

MALE PLEOPODS. Pl1 ( Fig. 15j ): endopod of male subrectangular, 2.5 times as long as wide, reaching 0.40 lenght of endopod, with an appendix on distal outer margin which reaches beyond distal end of endopod on a short length. Pl2 ( Fig. 15k ): appendix masculina reaching 0.57 times length of endopod; appendix interna reaching 0.75 of appendix masculina.

PRE- ANAL CARINA ( Fig. 15g ). High, unarmed.

UROPODAL DIAERESIS ( Fig. 15h ). With 17–21 spinules.

EGGS. Ovigerous females with eggs size: 0.35–0.42 × 0.19–0.25mm.

Habitat

This species is largely rheophile and prefers fresh and well-oxygenated waters from the higher course of rivers (148–276 m a.s.l.).

Colour pattern ( Fig. 26C )

Body covered in small dots, several red stripes, sometimes with a white dorsal band running from the rostrum to the telson.

Distribution

This species occurs in Indonesia (Sumba, Halmahera), Papua New Guinea (New Britain) and the Solomon Islands (Kolombangara and Malaita).

Remarks

Our specimens fit well with the types, described by De Man (1892) from Flores, by its P1 carpus 1.4–2.0 times as long as wide (vs 1.9–2.1 in type specimens); by its P2 carpus 4.8–5.5 times as long as wide (vs 4.9–5.4); by its P3 dactylus 2.8–3–7 times as long as wide (terminal spiniform seta included) (vs 3.2) with 6–8 spiniform setae on the flexor margin in addition to the terminal one (vs 6–7), propodus 9.5–12.7 times as long as wide (vs 9.0), 4.0–4.6 times as long as dactylus (vs 3.5–3.9): by its P5 dactylus 3.9–5.2 as long as wide (vs 4.6) with 47–66 spiniform setae on the flexor margin (vs 60–65), propodus 13.3–19.3 times as long as wide (vs 15.6) and 3.8–4.5 times as long as dactylus (vs 3.6); by its telson with one or two pairs of setae, lateral pair of setae distinctly longer than sublateral pair, both shorter than 6–11 intermediate setae (vs 8); by its eggs size 0.35– 0.42 × 0.19–0.25 mm (vs 0.39–0.40 × 0.23–0.26 m).

Our specimens are also similar to C. weberi as described by Cai & Ng (2001) from Halmahera ( Indonesia) in the shape of the rostrum, which is straight, reaching to base or near middle of second segment of antennular peduncle (see Fig. 3 A–B) with 0–2 teeth situated on carapace behind orbital, and also by its telson with two pairs of setae, lateral pair of setae distinctly longer than sublateral pair, both shorter than intermediate setae (see Fig. 3 C–E), its P5 dactylus with 47–66 spiniform setae on flexor margin (vs 55 according to Cai & Ng (2001)), and by its eggs size 0.35– 0.42 × 0.19–0.25 mm (vs 0.4– 0.2 mm). However, the rostrum has more teeth (0–2) 11–23/2–5 (vs (1–2) 13–14/2–3), P1 carpus longer 1.4–2.0 (vs 1.3), P5 propodus 3.8–4.5 times as long as dactylus (vs 5.0). We consider the observed differences to be within an intra-specific range.

It is also similar to C. weberi as described by Roux (1928) from Sumba by its rostrum formula (0–2) 11–23/2–5 (vs (1–2) 12–19/2–6 according to Roux (1928)), by its P1 carpus 1.4–2.0 times as long as wide (vs 1.5–2.1), its chela about 2.0–2.3 times as long as wide (vs 2–2.1), its P2 carpus 4.8–5.5 times as long as wide (vs 5–5.7), its P2 chela about 2.5–2.9 times as long as wide (vs 2.8–3.1), its P3 dactylus 2.8–3.7 times as long as wide (terminal spiniform seta included) (vs 3.1–3.8), with 6–8 spiniform setae on flexor margin in addition to the terminal one (vs 6–7), its P3 propodus 4.0–4.6 times as long as dactylus (vs 4.5–5.4), P5 dactylus 3.9–5.2 as long as wide (vs 4.4–5), with 47–66 spiniform setae (vs 62–70) on flexor margin, and its eggs size 0.35–0.42 × 0.19–0.25 mm (vs 0.35–0.38 × 0.20–0.21 mm). However, its P5 propodus is longer 3.8–4.5 times as long as the dactylus (vs 3.4–3.6). We think that the observed differences are also within an intra-specific range.

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. 15. Caridina weberi De Man, 1892. 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. First male pleopod. k. Second male pleopod. l. Eggs. m. Cephalothorax. MNHN-IU-2018-2867 (a–i, l–m) and MNHN-IU-2018-2870 (j–k).

Fig. 26. Live colourations. A. Caridina buehleri Roux, 1934 (MNHN-IU-2015-20). B. Caridina gueryi Marquet, Keith & Kalfatak, 2009 (MNHN-IU-2015-19). C. Caridina weberi De Man, 1892 (Kolombangara Island). D. Caridina serratirostris De Man, 1892 (MNHN-IU-2018-2931). E. Caridina papuana Nobili, 1905 (Choiseul Island). Habitats in the Solomon Islands. F. Caridina maeana sp. nov. (Choiseul Island). G. Lentic mode, Lodumoe river, Kolombangara Island. H. Lotic mode, Sulumuni river, Kolombangara Island. Photopgraphs by P. Keith (A, D–F, H) and C. Lord (B–C, G).

Fig. 3. Caridina barakoma 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. First male pleopod. k. Second male pleopod. l. Eggs. m. Cephalothorax. MNHN- IU-2014-20807 (a–i, l–m) and MNHN-IU-2014-20805 (j–k).