Tonna dunkeri

Tonna dunkeri, common name boxing glove, is a species of large sea snail, a marine gastropod mollusk in the family Tonnidae, the tun shells.

Description

The length of the shell attains 125 mm.

The shell is moderate to large, fragile and globular in shape. It features a very large aperture and a low spire. The surface is sculpted with well-developed, broad, flat-topped spiral cords, and the base has a pronounced siphonal notch. Adult animals lack an operculum. This species is highly variable, with both shallow- and deep-water forms. On the Agulhas Bank, shells tend to be more globular, with a lower spire, a pronounced shoulder, and a slightly sunken suture.

The color of fresh shells is light brown to orange-brown. The ribs are marked with irregular white blotches, bordered by darker brown bars.

Distribution

This marine species occurs off South Africa, off the Agulhas Bank and East coast at depths between 50 m and 100 m; also off Madagascar.

References

• Hanley, S. (1860a), Descriptions of New Univalve Shells from the Collections of H. Cuming and Sylvanus Hanley. Proceedings of the Zoological Society of London, 1859 27: 429-431
• Bayer, Ch. (1937) Catalogue of the Doliidae in the Rijksmuseum van Natuurlijke Historie. Overgedrukt uit Zoologiscshe Mededelingen XX, Leiden, E. J. Brill, page(s): 38
• Kilias, R. (1962) Das Tierreich, Lieferung 77, Gastropoda / Prosobranchia: 1-63, Walter de Gruyter & Co., Berlin. page(s): 35
• Kilburn R.N. (1971). On some species of the families Tonnidae, Hipponicidae, Buccinidae, Columbariidae, Fasciolariidae, Psammobiidae and Mactridae (Mollusca) in South African waters. Annals of the Natal Museum 20(3):483-497
• Steyn, D.G. & Lussi, M. (1998) Marine Shells of South Africa. An Illustrated Collector's Guide to Beached Shells. Ekogilde Publishers, Hartebeespoort, South Africa, ii + 264 pp. page(s): 70
• Vos, C. (1999) A new Tonna Brünnich, 1772 (Gastropoda: Tonnidae) from Gulf of Aden. Gloria Maris, Vol. 38, (1–6), p. 43–47, pl. 8-9 page(s): 44
• Vos, C. (2007) A conchological Iconography (No. 13) - The family Tonnidae. 123 pp., 30 numb. plus 41 (1 col.) un-numb. text-figs, 33 maps., 63 col. pls, Conchbooks, Germany page(s): 93

External links

• Barnard, K. H. (1963). Contributions to the knowledge of South African marine Mollusca. Part III. Gastropoda: Prosobranchiata: Taenioglossa. i>Annals of the South African Museum 47(1): 1-199.
• Herbert, D.G., Jones, G.J. & Atkinson, L.J. (2018). Phylum Mollusca. In: Atkinson, L.J. and Sink, K.J. (eds) Field Guide to the Offshore Marine Invertebrates of South Africa. Malachite Marketing and Media: Pretoria. Pp. 249–320