The Tonnidae are a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

of medium-sized to very large

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

s, known as the tun shells. These are

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

s in the clade

Littorinimorpha Littorinimorpha is a large order of snails, gastropods, consisting primarily of sea snails ( marine species), but also including some freshwater snails ( aquatic species) and land snails (terrestrial species).Bouchet P. & Rocroi J.-P. (Ed.); Fr� ...

. The name ''tun'' refers to the snails' shell shape, which resembles wine casks known as "tuns". While thin, the shells are also strong and lack opercula. They are found in all tropical seas, where they inhabit sandy areas. During the day, they bury themselves in the substrate, emerging at night to feed on

echinoderm An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea ...

s (especially

sea cucumber Sea cucumbers are echinoderms from the class Holothuroidea (). They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothuria ...

s),

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

, and

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

s. Some larger species also capture fish, using their expandable probosces to swallow them whole. Females lay rows of eggs that become free-swimming larvae for several months before settling to the bottom.

Taxonomy

In 2005, these subfamilies were recognized in the taxonomy of Bouchet & Rocroi: *

Cassinae The Cassidae are a taxonomic family of medium-sized, large, and sometimes very large sea snails commonly called helmet snails or bonnet snails. These are marine gastropod mollusks in the superfamily Tonnoidea and the clade Littorinimorpha.Go ...

Latreille, 1825 * Oocorythinae P. Fischer, 1885 * Phaliinae Beu, 1981 * Tonninae Suter, 1913 Bouchet & Rocroi (2005) listed Cassidae as a synonym of Tonnidae Suter, 1913 (1825), following Riedel (1995) in this. However, later Beu (2008: 272) separated the two families. This is in agreement with the action of Thiele (1925) who placed Tonnidae and Cassidae under "Tonnacea", therefore acting as first reviser under

ICZN The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the I ...

article 24. In this respect, the

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

follows the opinion of Beu.Gofas, S. (2011). Cassidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=22999 on 2011-02-23

Genera

Genera and species within the family Tonnidae include: The subfamily Cassinae has been raised to the rank of family

Cassidae The Cassidae are a taxonomic family of medium-sized, large, and sometimes very large sea snails commonly called helmet snails or bonnet snails. These are marine gastropod mollusks in the superfamily Tonnoidea and the clade Littorinimorpha.Go ...

* '' Eudolium'' Dall, 1889 * '' Malea'' Vallenciennes, 1832 * '' Tonna'' Brunnich, 1771 ;Genera brought into synonymy : * ''Cadium'' Link, 1807 : synonym of ''Tonna'' Brunnich, 1771 * ''Cadus'' Röding, 1798 : synonym of ''Tonna'' Brunnich, 1771 * ''Cassidaria'' Link, 1807 : synonym of ''Eudolium'' Dall, 1889 * ''Doliopsis'' di Monterosato, 1872 (non Vogt, 1852; non Conrad, 1865) : synonym of ''Eudolium'' Dall, 1889 * ''Foratidolium'' Rovereto, 1899: synonym of ''Tonna'' Brünnich, 1771 * ''Macgillivrayia'' Forbes, 1852 : synonym of ''Tonna'' Brünnich, 1771 * ''Dolium'' Lamarck, 1801: synonym of ''Tonna'' Brunnich, 1771 * ''Parvitonna'' Iredale, 1931: synonym of ''Tonna'' Brunnich, 1771 * ''Perdix'' Montfort, 1810: synonym of ''Tonna'' Brunnich, 1771 * ''Quimalea'' Iredale, 1929: synonym of Malea Valenciennes, 1832

References

External links

Checklist of Mollusca

Paleodb
{{Taxonbar, from=Q1517807

Taxonomy

Genera

Further reading

References

External links