High cryptic diversity in the kleptoparasitic genus Hyalorisia Dall, 1889 (Littorinimorpha: Capulidae) with the description of nine new species from the Indo-West Pacific Author Fassio, Giulia Author Russini, Valeria Author Buge, Barbara Author Schiaparelli, Stefano Author Modica, Maria Vittoria Author Bouchet, Philippe Author Oliverio, Marco text Journal of Molluscan Studies 2020 Rijksuniversiteit te Gent. Fakulteit van de Landbouwkundige en Toegepaste Biologische Wetenschappen 2020-09-18 86 4 401 421 http://dx.doi.org/10.1093/mollus/eyaa028 journal article 10.1093/mollus/eyaa028 613998a5-1f0e-46b2-9141-a0bce996b557 4464900 6DBF9C90-3CAA-49F3-A9ED-9611D073840F Hyalorisia madagascarensis Fassio, Bouchet & Oliverio new species MOTU-10 ( Figs 3J , 6B , 7H, Q ) Type material : Holotype : off Mahajanga, NW Madagascar , MIRIKY, Stn CP3268 , 15°31 S , 45°45 E , 640–800 m , MNHN-IM-2007-39090 . Material examined : The holotype and one other specimen ( MNHN-IM- 2007-39292). Etymology : After the general area of occurrence, Madagascar . ZooBank registration : urn:lsid:zoobank.org:act: 5D585AFC-B8C7-4639-9535-74CA13427627 . COI-based diagnosis : Nine diagnostic (autapomorphic) positions in the alignment: 40(G), 103(C), 158(C), 283(G), 529(C), 553(C), 556(C), 605(T) and 628(G). Shell (data for holotype shown within parentheses) : Size small to medium for genus: length 6.5–11 (6.5) mm, width 4.5–9 (4.5) mm, height 2–3 (2) mm; thin, ellipsoidal or rounded, depressed; white shell surface with smooth yellowish periostracum; anterior margin rounded; protoconch of 0.9 whorl, diameter of nucleus 0.19 mm ; teleoconch smooth except for distinct commarginal growth ridges; apertural margin thin, interior glossy white; lamella from wide to narrow, width 0.8–0.92 (0.8) mm. Soft parts (ethanol preserved) : Cephalic tentacles whitish with grey base; pseudoproboscis whitish. Radula : Taenioglossate, 2-1-R-1-2; marginal teeth sickle shaped; internal marginals with a few denticles on the inner edge; lateral teeth triangular, highly denticulated on both edges; rachidian tooth triangular, highly denticulated on both edges. Host : Holotype attached to P. caducum (MNHN-IM-2007-39094). The second specimen of this Hyalorisia species (MNHN-IM-2007-39092) has a registration number close to that of a specimen of P. sibogai (MNHN-IM-2007-39097); the latter shows a mark on the shell that corresponds to the contour of the Hyalorisia specimen. Distribution : So far known only from Madagascar , at depths 425– 640 m. Remarks : Off Mahajanga , Madagascar (MIRIKY: Stn CP3268), Hyalorisia madagascarensis n. sp. was found sympatrically with H. lehibe n. sp. (MOTU-5) and syntopically with H. kely n. sp. (MOTU-7).