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 gueryi Marquet, Keith & Kalfatak, 2009 Figs 2X , 13 , 26B Caridina gueryi Marquet, Keith & Kalfatak, 2009: 159–166 , figs 1–3 ( type locality: unnamed river, 15°17´45.30″ S , 167°9´35.98″ E , Santo, Vanuatu ). Caridina buehleri – Klotz et al. 2007: 3–7 . Material examined Holotype VANUATU • ♀ ovig., cl 6.8 mm ; Santo Island , unnamed river; 15°17´45.30″ S ; 167°9´35.98″ E ; 22 Jul. 2003 ; P. Keith and G. Marquet leg.; MNHN-IU-2015-1768. Paratypes VANUATU • 1 ♂, cl 3.6 mm ; same collection data as for holotype; DNA voucher: CA2428; MNHN- IU-2015-1769 • 1 ♀ ovig., cl 6.0 mm; same collection data as for holotype; MNHN-IU-2015-1771 • 1 ♀ ovig., cl 5.5 mm ; same collection data as for holotype; MNHN-IU-2015-1775 . Other material SOLOMON ISLANDS – Kolombangara Island • 1 ♀ ovig., cl 4.3 mm ; Jack Harbour River ; 08°03.085´S , 157°10.945´E ; 11 Nov. 2015 ; P. Keith , C. Lord and G. Marquet leg.; DNA voucher: CA1519; MNHN-IU- 2015-19 • 1 ♀ ovig., cl 3.9 mm ; Vagé River ; 08°5.112´S , 156°59.867´E ; 10 Nov. 2015 ; P. Keith , C. Lord and G. Marquet leg.; MNHN-IU- 2015-17 • 1 ♀ ovig., cl 4.5 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- 2015-21 . INDONESIA • 1 ♀ ovig., cl 6.4 mm ; Sulawesi , Luwuk Peninsula , W of Ampana , freshwater spring in Mallontong , brackish water pool (field code 70–05); 00°53.125´S , 121°31.371´E ; 27 May 2005 ; M. Glaubrecht , T. von Rintelen and K. Zitzler leg.; ZMB 29000 . VANUATU • 3 ♀♀ ovig., cl 5–6 mm ; Malekula Island , Brenwe River ; 16°07.593´S , 167°16.779´E ; 54 m a.s.l. ; 20 Nov. 2008 ; P. Feutry , P. Keith , C. Lord and L. Taillebois leg.; MNHN-IU- 2015-23 . Description CEPHALOTHORAX. Antennal spine below suborbital angle. Pterygostomian margin sub rectangular. Rostrum ( Fig. 13k ): 0.5–1.4 of cl, reaching to or overreaching distal end of scaphocerite, armed with 9–17 teeth on dorsal margin, 3–5 of them situated on carapace behind orbital margin, ventral margin with 2–7 teeth. Eyes well developed, anterior end reaching to 0.63 length of basal segment of antennular peduncle. Antennular peduncle 0.56–0.57 ( ♀ ) times as long as carapace. Anterolateral angle reaching 0.33 length of second segment, basal segment of antennular peduncle longer than sum of second and third segment lengths, second segment distinctly longer than third segment. Stylocerite sharp, long, reaching to about half of second segment of antennular peduncle. PEREIOPODS. Epipods on first four pereiopods. P1 ( Fig. 13 a–b): chela about 1.9–2.4 times as long as wide, movable finger 2.1–2.7 times as long as wide, 0.4–0.8 times length of palm; carpus 1.2–1.7 times as long as wide. P2 ( Fig. 13c ) more slender and longer than first pereiopod, with chela 2.2–3.0 times as long as wide: movable finger 3.0–4.8 times as long as wide, 1.0–1.7 times length of palm; carpus slender, 4.2–6.7 times as long as wide. P3 ( Fig. 13d ): dactylus ( Fig. 13f ) 2.9–4.0 times as long as wide (terminal spiniform seta included), with 6–7 spiniform setae on flexor margin in addition to terminal one; propodus 8.1–14.0 times as long as wide, 3.5–5.3 times as long as dactylus. P5 ( Fig. 13e ): dactylus ( Fig. 13g ) 3.3–4.4 times as long as wide as with 26–31 spiniform setae on flexor margin; propodus 12.3–20.5 times as long as wide, 4.4–6.2 times as long as dactylus. ABDOMEN. Third abdominal somite with moderately convex dorsal profile. Sixth abdominal somite 0.48 as long as carapace, 1.5 times as long as fifth somite, shorter than telson. TELSON ( Fig. 13j ). 2.5 times as long as wide, with 5–6 pairs of dorsal spinules and one pair of dorsolateral spinules; posterior margin with a median process, broadly convex with 7–12 plumose intermediate setae much longer than lateral. MALE PLEOPODS. Pl1: endopod subtriangular, 2.9 times as long as wide, reaching 0.37 times length of endopod, with an appendix on subdistal outer margin which reaches beyond distal end of endopod with most of its length. Pl2: appendix masculina reaching 0.57 times length of endopod; appendix interna reaching 0.60 of appendix masculina. PRE- ANAL CARINA ( Fig. 13h ). High, unarmed. UROPODAL DIAERESIS ( Fig. 13i ). With 17–19 spinules. EGGS. Size: 0.21–0.33 × 0.33–0.49. Fig. 13. Caridina gueryi Marquet, Keith & Kalfatak, 2009 . a . Details of the fingers of the first pereiopod. b . First pereiopod. c . Second pereiopod. d . Third pereiopod. e . Fifth pereiopod. f . Dactylus of third pereiopod. g . Dactylus of fifth pereiopod. h . Pre-anal carina. i . Uropodal diaeresis. j . Telson. k . Cephalothorax. MNHN-IU-2015-19 (a–k). Habitat This species lives in a typical brackish water environment (brackishwater pools or lower part of rivers, near the estuary). The species is rarely found over the superior limit of the tide-influenced zone, and was not found in the true freshwater zone. Colour pattern ( Fig. 26B ) Body usually dark red to black, with a lighter dorsal band from the rostrum to the telson and sometimes white stripes on each abdominal somite. Distribution This species occurs in the Solomon Islands (Kolombangara), in the Vanuatu archipelago (Malekula and Santo Islands) and in Indonesia ( Sulawesi ). Remarks Our specimens are distinguished from the holotype of C. buelheri from New Ireland by its long P5 propodus, 12.3–20.5 times as long as wide (vs short P5 propodus 9.4 in the holotype of C. buehleri ) and 4.4–6.2 times as long as the dactylus (vs 3.8). In contrast, they fit well with the holotype of C. gueryi from Santo (vs 12.3–15.9 and 4.6–5.2 in the holotype of C. gueryi , respectively). However, if we include other specimens of C. buehleri , the characters overlap, which is the reason why we previously mistakenly placed them in synonymy ( de Mazancourt et al. 2017a ). These two species can thus be considered to be cryptic. According to our molecular results, studied specimens from Sulawesi, the Solomon Islands and the Vanuatu archipelago belong to C. gueryi .