Otitoma cyclophora (Deshayes, 1863)

Fig. 1 A–L

Pleurotoma cyclophora Deshayes, 1863: 111, pl. 12, figs 19–21. Type locality: Réunion Island.

Daphnella crenulata Pease, 1868: 221, pl. 15, fig. 20. Type locality: Polynesia.

Otitoma ottitoma Jousseaume, 1898: 106 . Type locality Djibouti and Aden.

Mitrellatoma mitra Kilburn, 1986: 682, figs 97, 101. Type locality: Two Mile Reef, Benguera Island, Bazaruto Archipelago, southern Mozambique, 21°53′ S, 35°26′ E. syn. nov.

Material examined

FIJI ISLANDS: 1 spm, MUSORSTOM 10, Stn CP1366, S of Viti Levu, 18°12.4′ S, 178°33.1′ E, 149– 168 m; 1 spm, MUSORSTOM 10, Stn DW1381, S of Viti Levu, 18°17.8′ S, 177°54.4′ E, 275– 430 m.

SOUTHWEST PACIFIC: 1 spm, MUSORSTOM 7, Stn DW626, Banc Bayonnaise, 597– 600 m.

PHILIPPINES: 1 spm, Mactan Island, 10– 20 m.

MADAGASCAR: 1 spm, Tulear reef, 15– 20 m.

Remarks

This species, the type of the genus Otitoma, has a very broad distribution from the southern Red Sea and Mozambique to Japan, Fiji and Polynesia. Kilburn (2004) selected a neotype from Aden and redescribed the species on the basis of local material from Mozambique. The same author determined Daphnella crenulata Pease, 1868, described from Polynesia, to have been based on a juvenile specimen of O. cyclophora . Our material (Fig. 1 A–C, G–L) matches that figured and discussed by Kilburn (2004) in morphological features and is, accordingly, considered as conspecific. Kilburn (1986) introduced Mitrellatoma mitra for a single shell from Southern Mozambique; the taxon was later cited by the same author in his list of species belonging to the genus Otitoma (Kilburn 2004), but without a formal discussion of the reassignment. In our opinion, the holotype of Mitrellatoma mitra (Fig. 1 E–F) is a juvenile specimen that perfectly matches the morphological features of the lectotype of Daphnella crenulata, and the former species is also considered a synonym of O. cyclophora here.

Otitoma cyclophora has previously been considered a littoral species (Kilburn 2004), but the present records indicate it can also live in deep water (down to 600 m). The available specimen from deep water (Stn DW626) measures 13.7 × 4.0 mm, aperture height 6.4 mm and is the maximum size reported for the species. As already noted by Kilburn (2004), O. cyclophora has a well-developed secondary spiral sculpture of numerous closely-spaced, fine spiral threads (Fig. 1I).