''Tonna dolium'', common name the spotted tun, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of large

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

or tun snail, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Tonnidae The Tonnidae are a family (biology), family of medium-sized to very large sea snails, known as the tun shells. These are marine invertebrates, marine gastropod molluscs in the clade Littorinimorpha. The name ''tun'' refers to the snails' shell sh ...

, the tun shells.Vos, C. (2009). Tonna dolium. In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=208012 on 2016-05-22

Description

The size of the shell varies between 100 mm and 181 mm. The thin shell is ovate-globose and ventricose. The

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spire ...

is generally short. It is composed of six

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagra ...

s, slightly flattened above. The

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk ...

is large and very convex. All these whorls are encircled by wide and distant ribs, slightly convex, numbering ten upon the body whorl. Others, more narrow, are placed alternately within the furrows, which are wide and very slightly striated. The surface of this shell is of a white color, slightly grayish, and sometimes rose-colored. It is ornamented upon the ribs, with alternate white and red spots, often also orange, which, disposed thus in regular series, present a beautiful appearance. The

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is very large, colored within of a chestnut tint. The outer

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

is thin, notched, canaliculated within, and its edge is white and undulated. The inner lip is only slightly perceptible towards the base, where it forms a part of the umbilicus, which is hardly developed. The

columella Lucius Junius Moderatus Columella (, Arabic: ) was a prominent Roman writer on agriculture in the Roman Empire. His in twelve volumes has been completely preserved and forms an important source on Roman agriculture and ancient Roman cuisin ...

is twisted spirally, and furnished externally, even to the emargination of the base, with longitudinal ribs. Its ribs, wide and distant, its furrows equally wide, render it easily distinguishable.Kiener (1840). General species and iconography of recent shells : comprising the Massena Museum, the collection of Lamarck, the collection of the Museum of Natural History, and the recent discoveries of travellers; Boston :W.D. Ticknor,1837
(described as ''Dolium maculatum'')

Distribution

This marine species occurs in the Indo-West Pacific off

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

, the

Mascarene The Mascarene Islands (, ) or Mascarenes or Mascarenhas Archipelago is a group of islands in the Indian Ocean east of Madagascar consisting of islands belonging to the Republic of Mauritius as well as the French department of Réunion. Their na ...

Basin and off the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

References

* Linnaeus, C. 1758. ''Systemae naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differetiis, synonymis, locis.v. Holmiae'' : Laurentii Salvii 824 pp. * Martini, F.H.W. 1777. ''Neues systematisches Conchylien-Cabinet, fortgesetzt durch Johann Heironymus Chemnitz.'' Nürnberg : G. N. Raspe Vol. 3 vi + 1-434, pls 66-121. * Röding, P.F. 1798. ''Museum Boltenianum sive Catalogus cimeliorum e tribus regnis naturae quae olim collegerat Joa.'' Hamburg : Trappii 199 pp. * Lamarck, J.B.P.A. de M. 1822. ''Histoire naturelle des Animaux sans Vertèbres''. Paris : J.B. Lamarck Vol. 7 711 pp. * Springsteen, F.J. & Leobrera, F.M. 1986. ''Shells of the Philippines''. Manila : Carfel Seashell Museum 377 pp., 100 pls. * Drivas, J.; Jay, M. (1987). ''Coquillages de La Réunion et de l'Île Maurice''. Collection Les Beautés de la Nature. Delachaux et Niestlé: Neuchâtel. . 159 pp. * Wilson, B. 1993. ''Australian Marine Shells. Prosobranch Gastropods''. Kallaroo, Western Australia : Odyssey Publishing Vol. 1 408 pp. * Vos, C. & Terryn, Y. in Poppe, G.T. & Groh, K. (eds) 2007. ''A Conchological Iconography. The family Tonnidae''. Hackenheim, Germany : ConchBooks pp. 1–121, 63 pls.

External links

World Register of Marine Species entry
{{Taxonbar, from=Q1056619 Tonnidae Gastropods described in 1822

Description

Distribution

References

Further reading

External links