''Turbo marmoratus'', known as the green turban, the marbled turban or great green turban, is a large species of

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 ...

with a thick

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adje ...

operculum in the

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 ...

Turbinidae, the turban snails.WoRMS (2012). ''Turbo marmoratus'' Linnaeus, 1758. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=216369 on 2012-10-01 The shells of these large sea snails have a very thick layer of

nacre Nacre ( , ), also known as mother of pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer; it is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is f ...

; this species has been commercially fished as a source of mother of pearl.

Distribution

These large snails live in tropical reefs in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

(off

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

Aldabra Aldabra is the world's second-largest coral atoll, lying south-east of the continent of Africa. It is part of the Aldabra Group of islands in the Indian Ocean that are part of the Outer Islands of the Seychelles, with a distance of 1,120 k ...

and the Mascarene Basin) and tropical western Pacific oceans; also off

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

, Australia. They are

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

and feed on

algae Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...

Description

The distinctive shell grows to a length of 18 cm. The large, imperforate, solid shell is ventricose, as broad as long. Its color pattern is green, marbled with white and rich brown. The 6-7

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). Whorls in nature File:Photograph and axial plane floral ...

s are flattened or concave above, rounded and bearing two nodose keels below, and a stronger nodose carina above. It bears blunt tubercles, especially strong on the shoulders. Its large, circular

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

has a golden, pearly shine. The base of the shell is produced. The columellar region is more or less excavated. The subcircular operculum is somewhat concave within. Its outer surface is closely tuberculate and whitish. ''Turbo marmoratus'' is the host of the ectoparasitic

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...

'' Anthessius isamusi'' Uyeno & Nagasawa, 2012 The shell of marbled turbans is used as a source of

. The large opercula of ''Turbo marmoratus'' have been sold as paperweights or door stops.Man and mollusc
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References

* Oostingh, C.H., 1925. ''Report on a collection of recent shells from Obi and Halmahera, Molluccas''. Mededeelingen van de Landbouwhoogeschool Wageningen, 29(1):1-362. * Allan, J., 1950. ''Australian Shells: with related animals living in the sea, in freshwater and on the land.'' Georgian House, Melbourne. xix 470 pp.. * Drivas, J. & M. Jay (1988). ''Coquillages de La Réunion et de l'île Maurice'' * Wilson, B., 1993. ''Australian Marine Shells. Prosobranch Gastropods''. Odyssey Publishing, Kallaroo, WA * Alf A. & Kreipl K. (2003). ''A Conchological Iconography: The Family Turbinidae, Subfamily Turbininae, Genus Turbo''. Conchbooks, Hackenheim Germany.

External links

* {{Taxonbar, from=Q7853864 marmoratus Gastropods described in 1758 Taxa named by Carl Linnaeus Marine gastropods