''Malea pomum'', common name the Pacific grinning 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 ...

, 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 ...

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

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.

Description

The size of the shell varies between 40 mm and 90 mm. The somewhat thick shell is ovate and inflated. It has a whitish ground color, varied and spotted with square spots, of a yellow more or less reddish, alternating upon the transverse ribs, with other spots of a dull white. The short

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 composed of six convex

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, banded with ribs equally convex, wide, not distant, and divided by narrow, shallow furrows. 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 somewhat narrow, toothed upon both edges, colored yellow within. 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 dilated, particularly towards the base, and forms externally a very thick convex margin, the external part of which is sharp, undulated, and its internal surface furnished with ten or twelve transverse, distant teeth, resembling folds. The inner lip consists of a smooth plate, convex and white, which partially covers the body of the shell. 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 ...

presents a pretty deep emargination, above which are observed several transverse thick folds, and some others, less numerous, more oblique, and less distinctly marked. The color of the animal is of a beautiful white, marked upon its circumference with triangular flames of a violet brown. The tentacles are long, slender and pointed, spotted with brown, in the form of triple rings. The trunk is white, the tube very long, pointed with brown and violet at its extremity.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 pomum'')

Distribution

This marine species occurs in the

Red Sea The Red Sea is a sea inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab-el-Mandeb Strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and th ...

, the tropical

Indo-West Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the s ...

, 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 ...

; 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 ...

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

Mauritius Mauritius, officially the Republic of Mauritius, is an island country in the Indian Ocean, about off the southeastern coast of East Africa, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Ag ...

Mascarenes 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 ...

Houtman Abrolhos The Houtman Abrolhos (often called the Abrolhos Islands) is a chain of 122 islands and associated coral reefs in the Indian Ocean off the west coast of Australia about west of Geraldton, Western Australia. It is the southernmost true coral r ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

; off Australia (the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

and

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

References

Linnaeus, C. (1758). Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Editio decima, reformata. Laurentius Salvius: Holmiae. ii, 824 pp
* Iredale, T. 1931. ''Australian molluscan notes. No. 1.'' Records of the Australian Museum 18(4): 201-235, pls xxii-xxv * Tinker, S. 1949. ''The Hawaiian Tun Shells.'' Pacific Science 3(4): 302-306 * Kilias, R. 1962. ''Gastropoda/Prosobranchia. Tonnidae.'' Das Tierreich 77: 1-63 * Wilson, B.R. & Gillett, K. 1971. ''Australian Shells: illustrating and describing 600 species of marine gastropods found in Australian waters.'' Sydney : Reed Books 168 pp. * Kay, E.A. 1979. ''Hawaiian Marine Shells. Reef and shore fauna of Hawaii. Section 4 : Mollusca''. Honolulu, Hawaii : Bishop Museum Press Bernice P. Bishop Museum Special Publication Vol. 64(4) 653 pp. * Iredale, T. & McMichael, D.F. 1962. ''A reference list of the marine Mollusca of New South Wales.'' Memoirs of the Australian Museum 11: 1-109 * Wilson, B. 1993. ''Australian Marine Shells. Prosobranch Gastropods''. Kallaroo, Western Australia : Odyssey Publishing Vol. 1 408 pp. {{Taxonbar, from=Q1056282 Tonnidae Gastropods described in 1758 Taxa named by Carl Linnaeus