|Two views of a shell of Turbo marmoratus|
Turbo marmoratus, known as the green turban, the marbled turban or great green turban, is a large species of marine gastropod with a thick calcareous operculum in the family Turbinidae, the turban snails. 
The shells of these large sea snails have a very thick layer of nacre; this species has been commercially fished as a source of mother of pearl.
These large snails live in tropical reefs in the Indian Ocean (off Tanzania, Madagascar, Aldabra and the Mascarene Basin) and tropical western Pacific oceans; also off Queensland, Australia. They are nocturnal and feed on algae.
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 whorls 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 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. 
- 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
- G.W. Tryon (1888), Manual of Conchology X; Academy of Natural Sciences, Philadelphia
- Man and mollusc
- 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.
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