Hyalorisia kely Fassio, Bouchet & Oliverio

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: 416

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http://doi.org/ 10.1093/mollus/eyaa028

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scientific name

Hyalorisia kely Fassio, Bouchet & Oliverio

new species

Hyalorisia kely Fassio, Bouchet & Oliverio   new species

MOTU-7 ( Figs 3G View Figure 3 , 5C View Figure 5 , 7F, O View Figure 7 )

Type material: Holotype: off Mahajanga, NW Madagascar, MIRIKY, Stn CP3268 , 15°31 S, 45°45 E, 640–800 m, MNHN-IM-2007-39091 (male). GoogleMaps  

Material examined: The holotype and other material (MNHN-IM-2007-38809 and MNHN-IM-2007-39041).

Etymology: After the Malagasy adjective ‘kely’, meaning ‘little or small’, referring to the size of this species.

ZooBank registration: urn:lsid:zoobank.org:act:73192B98-3CD7-4500-A250-DE3F2DF78C5C .

COI-based diagnosis: Five diagnostic (autapomorphic) positions in the alignment: 325(G), 448(C), 514(G), 580(G) and 634(C).

Shell (data for holotype shown within parentheses): Size small for the genus: length 4–6.5 (6.5) mm, width 2.5–4.5 (4.5) mm, height 1.5–2.5 (2.5) mm; thin, ellipsoidal, depressed; white shell surface with a smooth yellowish periostracum; anterior margin very slightly angled; protoconch of 0.8–1 (1) whorl, diameter of nucleus 0.19–0.21 (0.19) mm; teleoconch smooth except for distinct commarginal growth ridges; apertural margin thin, interior glossy white; lamella narrow to wide, width 0.34–0.8 (0.8) mm.

Soft parts (ethanol preserved): Cephalic tentacles completely whitish or grey at the base; pseudoproboscis whitish.

Radula: Taenioglossate, 2-1-R-1-2; marginal teeth sickle shaped; internal marginals with few denticles on the inner edge; lateral teeth triangular, highly denticulated on outer edge, inner edge highly denticulated or presenting a single denticle; rachidian tooth triangular, highly denticulated on both edges.

Host: The holotype was attached to P. caducum   (MNHN-IM-2007-39095) ( Fig. 9B View Figure 9 ).

Distribution: So far known only from Madagascar and the Mozambique Channel, at depths of 357– 640 m.

Remarks: Hyalorisia kely   n. sp. was found off Mahajanga, Madagascar (MIRIKY: Stn CP3268). Here, it occurred sympatrically with H. lehibe   n. sp. (MOTU-5) and syntopically with H. madagascarensis   n. sp. (MOTU-10).