Hyalorisia tosaensis ( Otuka, 1939 )

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 : 414-415

Hyalorisia tosaensis ( Otuka, 1939)

MOTU-3 ( Figs 3C , 4C , 6E , 7C, L )

Capulus (Hyalorisia) tosaensis Otuka, 1939: 93 , 94 (Japanese text), 96, 97 (English text), figs 1–3 ( Bay of Tosa , Japan, 457 m; holotype, Seto Marine Biological Laboratory, Field Science Education and Research Center, Kyoto University, Japan) .

Material examined: Holotype (only photographic image examined; Fig. 8 D–F) and other material ( MNHN-IM-2007-34029 , MNHN-IM-2007-34199 , MNHN-IM-2007-34789 , MNHN-IM-2007-34790 , MNHN-IM-2007-34794 , MNHN-IM-2013-58350 , MNHN-IM-2013-58352 , MNHN-IM-2013-58358 , MNHN-IM-2013-58359 , MNHN-IM-2013-59236 , MNHN-IM-2013-59287 , MNHN-IM-2013-59698 and AORI_YK2262 ).

COI-based diagnosis: One diagnostic (autapomorphic) position in alignment: 50(C).

Shell (data for holotype shown within parentheses): Size medium to large for genus: length 7.68–19 (15.5) mm, width 5.2–15 (10.7) mm, height 2.8–5.44 (4.9) mm; thin, ellipsoidal or rounded, depressed; white shell surface with a smooth yellowish periostracum; anterior margin rounded or angled; protoconch of 0.9– 1 whorls, diameter of nucleus 0.09–0.25 mm; teleoconch smooth except for distinct commarginal growth ridges; apertural margin thin, interior glossy white; lamella from wide to narrow, width 0.6–1.8 (1.2) mm.

Soft parts (ethanol preserved): Head completely whitish or grey at the base; cephalic tentacles completely whitish or grey at the base or grey up to half of their length; pseudoproboscis whitish; mantle whitish or grey with whitish border; foot whitish or grey.

Radula: Taenioglossate, 2-1-R-1-2; marginal teeth sickle shaped; lateral teeth triangular, smooth or with few denticles on outer edge; rachidian tooth triangular with many or few denticles on both edges.

Host: Five specimens (MNHN-IM-2013-58350, MNHN-IM-2013-58352, MNHN-IM-2013-59236, MNHN-IM-2013-59287 and MNHN-IM-2013-59698) were found attached to each of five examples of P. sibogai (MNHN-IM-2013-58349, MNHN-IM-2013- 58351, MNHN-IM-2013-59235, MNHN-IM-2013-59286 and MNHN-IM-2013-59286, respectively). One specimen (MNHN-IM-2013-58359) was attached to P. investigatoris (MNHN-IM-2013-58396). The specimen collected in Japan (AORI_YK2262) was also found attached to P. sibogai . Five other specimens (MNHN-IM-2007-34029, MNHN-IM-2007-34789, MNHN-IM-2007-34790, MNHN-IM-2007-34794 and MNHN-IM-2013-58358) were found at stations where the only reported Propeamussium was P. sibogai . In the original description, Otuka also reported a specimen on Terebra pretiosa from Okinosima, Koti Prefecture (now Okinoshima, Kochi Prefecture, Japan), but this record is questionable (see Remarks under genus Hyalorisia ).

Distribution: So far known from Japan, the South China Sea, the Philippines, Papua New Guinea and the Solomon Islands, at depths of 278–1,045 m.

Remarks: In the original description, the protoconch is described as twisted to the left side. However, all the newly found specimens are dextrally coiled, and examination of the holotype has shown that the protoconch is actually dextral. Hyalorisia tosaensis was found sympatric with H. melanesica n. sp. (MOTU-8) in New Ireland, Papua New Guinea.

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 4. Shells of Hyalorisia. A. Hyalorisia galea, MNHN-IM-2013-60195, N of Grande-Terre, Guadeloupe (L = 13 mm). B. Hyalorisia neocaledonica n. sp., holotype, MNHN-IM-2013-65645, Lord Howe Rise, New Caledonia (L = 9.5 mm). C. Hyalorisia tosaensis, MNHN-IM-2013-58352, New Ireland, Papua New Guinea (L = 15 mm). D. Hyalorisia nupta n. sp., holotype, MNHN-IM-2007-34010, Bellona Reefs, New Caledonia (L = 18.5 mm). Scale bars = 2 mm.

Figure 6. Shells of Hyalorisia (A–C) and detail of the lamella (D, E). A. Hyalorisia profunda, holotype, MNHN-IM-2013-59695, South China Sea (L = 7 mm). B. Hyalorisia madagascarensis n. sp., holotype, MNHN-IM-2007-39090, off Mahajanga, Madagascar (L = 6.5 mm). C. Hyalorisia solomonensis n. sp., holotype, MNHN-IM-2007-34203, SE of Santa Isabel, Solomon Islands (L = 8 mm). D. Wide lamella of Hyalorisia neocaledonica n. sp., MNHN-IM-2013-65645, Lord Howe Rise, New Caledonia. E. Narrow lamella of Hyalorisia tosaensis, MNHN-IM-2013-58352, New Ireland, Papua New Guinea. Scale bars = 2 mm.

Figure 7. Radulae of Hyalorisia (A–I) and detail of the rachidian tooth (J–R). A, J. Hyalorisia galea MNHN-IM-2013-60195. B, K. Hyalorisia neocaledonica n. sp., MNHN-IM-2013-65647. C, L. Hyalorisia tosaensis, MNHN-IM-2013-58352. D, M. Hyalorisia nupta n. sp., MNHN-IM-2013-68952. E, N. Hyalorisia nanhaiensis n. sp., MNHN-IM-2013-59697. F, O. Hyalorisia kely n. sp., MNHN-IM-2007-38809. G, P. Hyalorisia melanesica n. sp., MNHN-IM-2007-34205. H, Q. Hyalorisia madagascarensis n. sp., MNHN-IM-2007-39090. I, R. Hyalorisia solomonensis n. sp., MNHN-IM-2007-34215. Scale bars = 100 µm.

Figure 8. A–C. Holotype of Capulus (Hyalorisia) galea Dall, 1889, USNM 508724, off Barbados. D–F. Holotype of Capulus (Hyalorisia) tosaensis Otuka, 1939, Seto Marine Biological Laboratory, collected from Bay of Tosa, Japan. G–I. Syntype of Capulus fragilis E. A. Smith, 1904, NHMUK 1904.6.15.136, Laccadive Sea. J. Original figure of Capulus fallax S. V. Wood, 1842 (Wood, 1842: pl. 17, fig. 4a, b), Lower Pliocene of England. K–N. Holotype of Capulus (Hyalorisia) nettlesi J. E. Robinson, 1983, PRI 30058, Upper Eocene of Mississippi. Scale bars: A–E, G–I, K–N = 10 mm; F = 5 mm. Photo credits: A–C, USNM; D–F, Kyoto University (taken by Ryutaro Goto); G–I, NHMUK (taken by Harry Taylor); K–N, Paleontological Research Institution, Ithaca, NY.