Hyalorisia lehibe Fassio, Bouchet & Oliverio, 2020

Fassio, Giulia, Russini, Valeria, Buge, Barbara, Schiaparelli, Stefano, Modica, Maria Vittoria, Bouchet, Philippe & Oliverio, Marco, 2020, High cryptic diversity in the kleptoparasitic genus Hyalorisia Dall, 1889 (Littorinimorpha: Capulidae) with the description of nine new species from the Indo-West Pacific, Journal of Molluscan Studies (Rijksuniversiteit te Gent. Fakulteit van de Landbouwkundige en Toegepaste Biologische Wetenschappen) 86 (4), pp. 401-421 : 415

Hyalorisia lehibe Fassio, Bouchet & Oliverio new species

MOTU-5 ( Figs 3E , 5A )

Type material: Holotype: off Mahajanga, NW Madagascar, MIRIKY, Stn CP3253 , 15°25 S, 45°55 E, 943–950 m, MNHN-IM-2007-39212 . One paratype: same locality as holotype, MNHN-IM-2007-39206 .

Etymology: After the Malagasy adjective ‘lehibe’, meaning ‘big or large’, referring to the size of this species.

ZooBank registration: urn:lsid:zoobank.org:act:FCF15E07-177B-4E13-B2DF-0DD8E9261DC8 .

COI-based diagnosis: Four diagnostic (autapomorphic) positions were scored in the alignment: 157(C), 292(G), 469(G) and 631(G).

Shell (data for holotype shown within parentheses): Medium sized for the genus: length 15–17 (15) mm, width 12.5–14.5 (12.5) mm, height 4–5 (4) mm; thin, rounded, depressed; white shell surface with smooth yellowish periostracum; anterior margin slightly angled; protoconch (intact only in holotype) of 1.1 whorls, diameter of nucleus 0.13 mm; teleoconch smooth except for distinct commarginal growth ridges; apertural margin thin, interior glossy white; lamella wide, width 1.8–2.48 (1.8) mm.

Soft parts: Not examined; damaged due to tissue clipping.

Host: The holotype was found attached to P. watsoni (MNHN-IM-2007-39211). The paratype (MNHN-IM-2007-39206) was found at the same station and has a registration number that is close to those of two specimens of P. watsoni (MNHN-IM-2007- 39209 and MNHN-IM-2007-39210); the shells of both bivalves bear a mark that corresponds to the contour of the Hyalorisia specimen.

Distribution: So far known only from the Madagascar side of the Mozambique Channel, at depths of 943– 950 m.

Remarks: Hyalorisia lehibe n. sp. was found off Mahajanga, NW Madagascar, where it occurred sympatrically with H. madagascarensis n. sp. (MOTU-10) and H. kely n. sp. (MOTU-7).

Figures

Figure 3. Protoconchs of Hyalorisia. A. Hyalorisia galea, MNHN-IM-2013-61536. B. Hyalorisia neocaledonica n. sp., MNHN-IM-2013-65907. C. Hyalorisia tosaensis, MNHN-IM-2007-34794. D. Hyalorisia nupta n. sp., MNHN-IM-2007-34005. E. Hyalorisia lehibe n. sp., MNHN-IM-2007-39212. F. Hyalorisia nanhaiensis n. sp., MNHN-IM-2013-34796. G. Hyalorisia kely n. sp., MNHN-IM-2007-38809. H. Hyalorisia melanesica n. sp., MNHN-IM-2013-58359. I. Hyalorisia profunda n. sp., MNHN-IM-2007-33828. J. Hyalorisia madagascarensis n. sp., MNHN-IM-39292. K. Hyalorisia solomonensis n. sp., MNHN-IM-2007-34215. Scale bars = 100 µm.

Figure 5. Shells of Hyalorisia. A. Hyalorisia lehibe n. sp., holotype, MNHN-IM-2007-39212, off Mahajanga, Madagascar (L = 15 mm). B. Hyalorisia nanhaiensis n. sp., holotype, MNHN-IM-2013-59534, S of Dongsha (=Pratas) Islands, South China Sea (L = 8.5 mm). C. Hyalorisia kely n. sp., holotype, MNHN-IM- 2007-39091, off Mahajanga, Madagascar (L = 6.5). D. Hyalorisia melanesica n. sp., holotype, MNHN-IM-2007-33873, Bellona Reefs, New Caledonia (L = 6.6 mm). Scale bars = 2 mm.