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 pisuku sp. nov. urn:lsid:zoobank.org:act: C2046392-256D-4485-8E85-8E94B9A37FF8 Figs 2M , 9 C. longirostris – Page et al. 2007: 647 (GenBank: DQ478506 – DQ478507 ). Caridina sp. 3 Solomon – de Mazancourt et al. 2019a: 166 , 169–170. Etymology Named after the river Pisuku, in Choiseul Island, the type locality where this new species occurs. The name is used as a noun in apposition. Material examined Holotype SOLOMON ISLANDS – Choiseul Island • ♂, cl 3.7 mm ; Choiseul Island , 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-2014-20862. Paratypes SOLOMON ISLANDS • 1 ♂, cl 3.7 mm ; same collection data as for holotype; MNHN-IU-2014-20863 • 1 ♀ ovig., cl 5.6 mm ; same collection data as for holotype; DNA voucher: CA1282; MNHN- IU-2014-20864 • 1 ♀ ovig., cl 5.8 mm ; same collection data as for holotype; DNA voucher: CA1347; MNHN-IU-2014-20865 • 1 ♀ , cl 4.8 mm ; same collection data as for holotype; MNHN-IU-2014-20866 • 1 ♀ , cl 5.0 mm; same collection data as for holotype; MNHN-IU-2014-20867 • 1 ♀ , cl 5.1 mm ; same collection data as for holotype; MNHN-IU-2014-20868 • 1 ♀ , cl 5.0 mm; Pisuku River , sector 2; 06°58.900´S , 156°46.685´E ; 66 m a.s.l. ; 10 Oct. 2014 ; P. Gerbeaux , P. Keith and G. Marquet leg.; MNHN-IU-2014-20869 • 1 ♀ , cl 5.1 mm ; same collection data as for preceding; MNHN-IU-2014-20870 • 1 ♂, juvenile, cl 2.2 mm ; Pisuku River , downstream; 06°58.848´S , 156°46.582´E ; 12 Oct. 2014 ; P. Gerbeaux , P. Keith and G. Marquet leg.; MNHN-IU-2014-20871 . Other material AUSTRALIA – Queensland • 1 ♂, cl 4.4 mm ; Christian Creek ; 17°20.100´S , 145°55.400´E ; 34 m a.s.l. ; 6 Jun. 2016 ; B. Mos leg.; MNHN-IU-2014-20873 • 1 ♀ ovig., cl 6.7 mm ; same collection data as for preceding; DNA voucher: CA1685; MNHN-IU-2014-20874 • 1 ♂, cl 4.6 mm ; Gordons Creek ; 16°57.967´S , 145° 43.833´E ; 39 m a.s.l. ; 3 Jun. 2016 ; B. Mos leg.; DNA voucher: CA1699; MNHN- IU-2014-20875 . INDONESIA • tissue only; West Papua , Kayumera ; 03°53.286´S , 134°28.658´E ; 22 Oct. 2010 ; P. Keith leg.; MNHN-IU-2014-20872 . Comparative material Caridina variabilirostris (de Mazancourt, Marquet & Keith, 2018 ) See de Mazancourt et al. (2018a) . Caridina brachydactyla (De Man, 1908) INDONESIA • lectotype (designated by Richard & Clark 2010 ), ♀ ovig., cl 4.8 mm ; Flores Island , river near Reo ; Nov. 1888 ; M. Weber leg.; RMNH Crust D. 977 • 2 paralectotypes , ♀♀ ovig., cl 5.3–5.4 mm ; Flores Island , river in Mbawa ; Jan. 1889 ; M. Weber leg.; RMNH 2552 • 1 ♀ , cl 5.8 mm ; Bali Island ; NMB 1054 a • 2 ♂♂, cl 2.7–3.7 mm , 1 ♀ ovig., cl 4.3 mm , 1 ♀ , cl 4.8 mm ; Sulawesi , Palopo , Macaui (locality code: 63.10); W. Klotz leg.; ZMB • 1 ♀ ovig., cl 4.0 mm; Sulawesi , Palopo , Tojo (locality code: 64.10); W. Klotz leg.; ZMB . Caridina elongapoda ( Liang & Yan, 1977 ) CHINA • 3 ♂♂, cl 2.8–3.5 mm , 1 ♀ , cl 4.2 mm ; Hong Kong, Pak Tam Chung and Kai Sai Chau (locality codes 14.11 and 22.09); W. Klotz leg.; ZMB. MALAYSIA • 1 ♂, cl 4.2 mm , 1 ♀ , cl 4.3 mm , 1 ♀ ovig., cl 4.3 mm ; Pulau Tioman , Sungai Asah ; 24 Jun. 1997 ; Ng et al. leg.; ZRC 1998.0865 . Caridina peninsularis ( Kemp, 1918 ) MALAYSIA • lectotype (designated by Cai et al . 2007), ♂, cl 3.2 mm ; Penang Island , Botanical Garden ; Feb. 1916 ; N.Anandale leg.; MNHN-IU-2015-1749 • 1 paralectotype , ♀ ovig., cl 5.4 mm ; same collection data as for lectotype; MNHN-IU-2015-1750 • 1 paralectotype , ♀ , cl 3.4 mm , 1 paralectotype , ♀ ovig., cl 5.2 mm , 1 paralectotype , ♂, cl 3.9 mm ; same collection data as for lectotype; NHM 1919.11.1.12-21 (1761124) . SINGAPORE • 1 ♀ ovig., cl 5.1 mm , 1 ♂, cl 4.2 mm ; Tanglin [incorrectly spelt Tangtum in NHM register and on label, see Richard & Clark 2014]; 1958; Bedford and Lanchester leg.; NHM 1958.8.7.14–17 (1749569) . Caridina variabilis ( de Mazancourt, Rogers & Keith, 2018 ) See de Mazancourt et al. (2018b) . Caridina sundanella ( Holthuis, 1978 ) INDONESIA • 1 syntype , ♂, cl 3.6 mm , 1 syntype , ♀ , cl 5.2 mm ; Sumba Island , West Sumba , 4 km N of Waimangura , Waikamburu Brook , Station 450; 250 m a.s.l. ; 19 Aug. 1949 ; E. Sutter and A. B̹hler leg.; NMB 989 a . Description CEPHALOTHORAX. Carapace ( Fig. 9m ) smooth, glabrous, with sharp antennal spine placed at lower orbital angle. Pterygostomial margin rounded. Antennular peduncle 0.64 ( ♀ ) – 0.80 (♂) times as long as carapace. Long rostrum ( Fig. 9 m–o), 0.8–1.1 of cl, 17–28 dorsal teeth closely set, leaving 0.20–0.80 of length unarmed distally, 1–3 post-orbital teeth present. 6–18 teeth present of ventral margin extending from proximal end either to tip or with short distal part unarmed. Number of dorsal teeth on rostrum behind first ventral tooth 11–21. PEREIOPODS. Slender P1 ( Fig. 9a ): chela about 1.7–2.2 times as long as wide, dactylus 2.6–3.9 times as long as wide, 1.1–1.7 length of palm; carpus 1.4–2.6 times as long as wide with shallow excavation on anterior margin. P2 ( Fig. 9b ) more slender and longer than first pereiopod: chela 2.2–2.6 times as long as wide, dactylus 3.9–5.2 times as long as wide, 1.2–2.1 times length of palm; carpus 4.8–5.7 times as long as wide. P3 ( Fig. 9c ): dactylus ( Fig. 9e ) 3.0–3.4 times as long as wide (terminal spiniform setae included), with 5–7 spiniform setae on flexor margin in addition to terminal one; propodus 10.6–17.9 times as long as wide, 4.1–6.2 times as long as dactylus. P5 ( Fig. 9d ): dactylus ( Fig. 9f ) 3.3–5.1 times as long as wide, with 22–46 spiniform setae on flexor margin; propodus 18.3–26.2 times as long as wide, 4.9–7.6 times as long as dactylus. Fig. 9. Caridina pisuku 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. n–o . Rostrum variations. MNHN-IU-2014-20865 (a–f, l), MNHN-IU-2014-20873 (g–h, j–k), MNHN- IU-2014-20864 (m), MNHN-IU-2014-20868 (i, n) and MNHN-IU-2014-20862 (o). ABDOMEN. Typical dorsal hump over third abdominal somite. Sixth abdominal somite 0.64 as long as carapace, 1.6 times as long as fifth somite, slightly shorter than telson. TELSON ( Fig. 9i ). 3.5 times as long as wide, four pairs of dorsal spinules and one pair of dorsolateral spinules; posterior margin with median process, distal setae short, lateral pair slightly longer than intermediate setae (4–5). MALE PLEOPODS. Pl1 ( Fig. 9j ): endopod subtriangular, 2.1 times as long as wide, 0.19 times as long as exopod, with appendix interna placed at distal end. Pl2 ( Fig. 9k ): appendix masculina reaching 0.60 times length of endopod; appendix interna reaching 0.66 of appendix masculina. PRE- ANAL CARINA ( Fig. 9g ). With spine. UROPODAL DIAERESIS ( Fig. 9h ). With 10–16 spinules. EGGS ( Fig. 9l ). Size: 0.36–0.47 × 0.28–0.29mm . Habitat This species prefers fresh and well-oxygenated waters. It is found only in the lower course of rivers. Colour pattern Unknown. Distribution This species was found on Choiseul Island ( Solomon Islands ), Indonesia ( West Papua ) and Australia ( Queensland ). Remarks Caridina pisuku sp. nov. looks like C. variabilis and C. variabilirostris from Micronesia by the number of teeth and their placement on the rostrum, the proportions between the joints of pereiopods and egg size. However, it can be distinguished by the presence of a spine on the pre-anal carina (vs the pre-anal carina always unarmed in C. variabilis and C. variabilirostris ). Caridina pisuku sp. nov. is most similar to C. brachydactyla De Man, 1908 , C. elongapoda Liang & Yan, 1977 , C. mertoni Roux, 1911 , C. peninsularis Kemp, 1918 and C. sundanella Holthuis, 1978 . In contrast to C. elongapoda , C. mertoni and C. sundanella , our new species has a spine on the pre-anal carina, like in C. brachydactyla and C. peninsularis , but its P2 chela is stouter 2.2–2.6 times as long as wide (vs 2.7–3.2 and 2.8–3.0, respectively). Caridina pisuku sp. nov. looks like C. choiseul sp. nov. by the number of teeth and their placement on the rostrum, the proportions between the joints of pereiopods, and the size of the eggs. However, the pre-anal carina always has a spine (vs the pre-anal with a spine or not in C. choiseul sp. nov. ) and the pterygostomial margin is rounded (vs subrectangular).