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 Author Mazancourt, Valentin de 334E54F3-9FE1-4208-8861-1946579697A5 Unité Biologie des organismes et écosystèmes aquatiques (BOREA), Muséum national d’Histoire naturelle, Sorbonne Université, Université de Caen Normandie, Université des Antilles, CNRS, IRD, CP 26, 57 rue Cuvier 75005 Paris, France. Museum f ̹ r Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, 10115 Berlin, Germany. Ecological Solutions in Solomon Islands, Western province, Gizo, Solomon Islands. valentin.demazancourt@laposte.net Author Boseto, David E2AA5328-9578-4380-9254-3FA0B65807E6 Ecological Solutions in Solomon Islands, Western province, Gizo, Solomon Islands. dboseto@ecologicalsolutions-si.com Author Marquet, Gerard BB110358-4FA2-4F5B-BF3A-B51F69D81AA9 Unité Biologie des organismes et écosystèmes aquatiques (BOREA), Muséum national d’Histoire naturelle, Sorbonne Université, Université de Caen Normandie, Université des Antilles, CNRS, IRD, CP 26, 57 rue Cuvier 75005 Paris, France. Museum f ̹ r Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, 10115 Berlin, Germany. Ecological Solutions in Solomon Islands, Western province, Gizo, Solomon Islands. gmarquet@neuf.fr Author Keith, Philippe FDDE84AB-E459-401C-A9BF-3F16CEEBFD7C Unité Biologie des organismes et écosystèmes aquatiques (BOREA), Muséum national d’Histoire naturelle, Sorbonne Université, Université de Caen Normandie, Université des Antilles, CNRS, IRD, CP 26, 57 rue Cuvier 75005 Paris, France. Museum f ̹ r Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, 10115 Berlin, Germany. Ecological Solutions in Solomon Islands, Western province, Gizo, Solomon Islands. keith@mnhn.fr text European Journal of Taxonomy 2020 2020-08-04 696 1 86 journal article 21373 10.5852/ejt.2020.696 5e1d0e63-c052-42fa-ba84-55f2166bfefd 3973435 265EDD08-7AA8-4835-B7F6-353E7992633E Caridina papuana Nobili, 1905 Figs 2N , 14 , 26E Caridina weberi var. papuana Nobili, 1905: 481 , pl. XII, fig. 1. Caridina weberi var. papuana – Roux 1917: 591 ; 1928: 204–205 ; 1934: 221–222 . — Bouvier 1925: 246 . Caridina cf. weberi papuana – Page et al. 2007: 649 (GenBank: DQ478543 – DQ478544 ). Caridina papuana – de Mazancourt et al. 2019a: 166 , 169–170. Material examined Lectotype (here designated) PAPUA NEW GUINEA • ♂, 3.2 mm ; “German New Guinea”, Stephansort, in a small stream in the forest; L. Biró leg.; HNHM 1124-1893 . Paralectotypes PAPUA NEW GUINEA • 4 ♂♂, cl 2.5–3.1 mm , 2 ♀♀ ovig., cl 4.1–4.6 mm ; same collection data as for holotype; HNHM 1124-1893 . Other material SOLOMON ISLANDS – Choiseul Island • 1 ♂, cl 3.2 mm ; Creek 1; 06°59.085´S , 156°47.454´E ; 132 m a.s.l. ; 14 Oct. 2014 ; P. Gerbeaux , P. Keith and G. Marquet leg.; MNHN-IU- 2018-2850 • 1 ♂, cl 3.3 mm ; Creek 2; 06°59.085´S , 156°47.913´E ; 93 m a.s.l. ; 14 Oct. 2014 ; P. Gerbeaux , P. Keith and G. Marquet leg.; MNHN-IU- 2018-2851 • 1 ♂, cl 3.6 mm ; same collection data as for preceding; MNHN-IU- 2018-2852 • 1 ♀ , cl 3.2 mm ; same collection data as for preceding; MNHN-IU- 2018-2853 • 1 ♀ , cl 5.1 mm ; same collection data as for preceding; MNHN-IU- 2018-2854 • 1 ♀ ovig., cl 4.6 mm ; same collection data as for preceding; MNHN-IU- 2018-2855 • 1 ♀ ovig., cl 3.4 mm ; Lopakare River ; 07°01.613´S , 156°46.567´E ; 20 Oct. 2014 ; P. Gerbeaux , P. Keith and G. Marquet leg.; DNA voucher: CA1361; MNHN-IU- 2018-2856 • 1 ♀ ovig., cl 3.4 mm ; same collection data as for preceding; MNHN- IU- 2018-2857 • 1 ♀ ovig., cl 3.4 mm ; same collection data as for preceding; MNHN-IU- 2018-2858 • 1 ♀ ovig., cl 3.5 mm ; same collection data as for preceding; MNHN-IU- 2018-2859 • 1 ♀ ovig., cl 3.6 mm ; same collection data as for preceding; MNHN-IU- 2018-2860 • 1 ♀ , 4.6 mm ; same collection data as for preceding; MNHN-IU- 2018-2861 • 1 ♀ , 4.6 mm ; same collection data as for preceding; DNA voucher: CA1286; MNHN-IU- 2018-2862 • 1 ♀ , cl 5.0 mm; Pisuku River , sector 1; 06°58.951´S , 156°46.582´E ; 15 m a.s.l; 10 Oct. 2014 ; P. Gerbeaux , P. Keith and G. Marquet leg.; MNHN-IU- 2018-2863 • 1 ♀ ovig., cl 4.1 mm ; Gu’ma River ; 07°01.764´S , 156°49.899´E ; 50 m a.s.l. ; 17 Oct. 2014 ; P. Gerbeaux , P. Keith and G. Marquet leg.; MNHN-IU- 2018-2864 • 1 ♀ ovig., cl 5.3 mm ; same collection data as for preceding; MNHN-IU- 2018-2865 • 1 ♀ , cl 4.7 mm ; same collection data as for preceding; MNHN- IU- 2018-2866 . Comparative material Caridina weberi De Man, 1892 INDONESIA • 3 syntypes , 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 . Description CEPHALOTHORAX. Suborbital angle indistinguishably fused with antennal spine. Pterygostomian margin rounded. Rostrum ( Fig. 14m ): curved down, short, 0.3–0.4 of cl, sometimes reaching middle of second segment of antennular peduncle, armed with 9–11 teeth on dorsal margin, 0–1 of them situated on carapace behind orbital margin, ventral margin with 2–4 teeth. Eyes well developed, anterior end reaching to 0.67 length of basal segment of antennular peduncle. Antennular peduncle 0.66 times as long as carapace. Anterolateral angle reaching 0.30 length of second segment, second segment of equal length with third segment. Stylocerite reaching to 0.8 length of basal segment of antennular peduncle. PEREIOPODS. Epipods on first four pereiopods. P1 ( Fig. 14a ): chela about 1.9–2.1 times as long as wide, movable finger 2.6–3.2 times as long as wide, 0.7–0.9 times length of palm; short carpus 1.3–1.5 times as long as wide. P2 ( Fig. 14b ) More slender and longer than first pereiopod, with chela 2.2–2.5 times as long as wide: movable finger 4.3–5.0 times as long as wide, 1.6–2.0 times length of palm; carpus slender, 4.2–5.1 times as long as wide. P3 ( Fig. 14c ): stout, dactylus ( Fig. 14e ) 3.0–3.2 times as long as wide (terminal spiniform seta included), with 5–6 spiniform setae on flexor margin in addition to terminal one; propodus 8.9–10.7 times as long as wide, 3.8–4.5 times as long as dactylus. P5 ( Fig. 14d ): dactylus ( Fig. 14f ) 2.8–3.9 as long as wide, with 25–31 spiniform setae on flexor margin, first setae enlarged; propodus 12.1–15.1 times as long as wide, 4.2 5.0 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, slightly shorter than telson. TELSON ( FIG. 14i ). 2.6 times as long as wide, with four or five pairs of dorsal spinules and one pair of dorsolateral spinules; posterior margin without a median process, rounded, with 5–9 very long intermediate setae longer than lateral. MALE PLEOPODS. Pl1 ( Fig. 14j ): endopod subrectangular, 3 times as long as wide, reaching 0.43 times length of endopod, with an appendix on subdistal outer margin which reaches beyond distal end of endopod on a short length. Pl2 ( Fig. 14k ): appendix masculina reaching 0.76 times length of endopod; appendix interna reaching 0.64 of appendix masculina. Fig. 14. Caridina papuana Nobili, 1905 . 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-2018-2856 (a–f, l), MNHN-IU-2018-2850 (g, j–k) and MNHN-IU-2018-2857 (h, m), MNHN-IU-2018-2859 (i). PRE- ANAL CARINA ( Fig. 14g ). High, unarmed. UROPODAL DIAERESIS ( Fig. 14h ). With 14–21 spinules. EGGS. Size: 0.36–0.44 × 0.21–0.26mm . Habitat This species is largely rheophile and prefers fresh and well-oxygenated waters from the lower to the higher course of rivers. Colour pattern ( Fig. 26E ) Body dark all over, sometimes with a white dorsal band running from the rostrum to the telson. Distribution This species occurs in the Solomon Islands ( Choiseul ) and in Papua New Guinea . Remarks All former mentions of this taxa were subspecific; given the results of our study, we decided to erect it to specific level ( de Mazancourt et al . 2019a ). Our specimens fit well with the types from Papua New Guinea : Rostrum curved down, short, 0.3–0.4 of cl (vs 0.4 in type specimens) sometimes reaching middle of the second segment of the antennular peduncle, armed with 9–11 teeth on the dorsal margin (vs 9–14), 0–1 of them situated on the carapace behind the orbital margin (vs 0), ventral margin with 2–4 teeth (vs 2–5); P1 carpus 1.3–1.5 times as long as wide (vs. 1.4–1.7); P2 carpus 4.2–5.1 times as long as wide (vs 4.5–5.5); P3 dactylus with 5–6 spiniform setae (vs 5), propodus 3.8–4.5 times as long as dactylus (vs 4.3); P5 dactylus with 25–31 spiniform setae (vs 25); uropodal diaresis 14–21 (vs 17–19); small eggs, 0.36–0.44 × 0.21–0.26 mm (vs 0.33–0.38 × 0.24–0.29); appendix interna on the endopod of the male first pleopod. Some specimens from Gu’ma River have one tooth situated on the carapace behind the orbital margin. However, their P5 are similar to those of C. papuana , with the dactylus 3.5 times as long as wide (vs 2.8–3.9), with 27 spiniform setae on the flexor margin (vs 25–31) and propodus 12.1 times as long as wide (vs 12.1–15.1), 4.4 times as long as dactylus (vs 4.2 5.0).