|A live individual of Monetaria annulus|
|A shell of Monetaria annulus|
The shell size varies between 9 mm and 50 mm. The shell of this species is mostly off-white or pale yellowish in color, sometimes with a dark cast on the dorsum, and with two yellow or orange stripes along the upper sides. These stripes nearly touch at the ends, giving the impression of a ring.
This species and its subspecies are found in the Red Sea, and in the Indian Ocean on the coasts of Aldabra, Chagos, the Comores, the East Coast of South Africa, Kenya and Tanzania, Madagascar, the Mascarene Basin, Mauritius, Mozambique, Réunion, the Seychelles, Somalia, Yemen, Oman, Maldives, India, Sri Lanka, Mozambique, in the tropical Pacific Ocean as far north as Hawaii and towards the western Pacific reaching the Galápagos islands.
There may be three or more subspecies:
- Monetaria annulus camelorum,
- Monetaria annulus sublitorea and
- Monetaria annulus obvelata (Rochebr.)
Use as shell money
In parts of Asia, Africa and the Middle East, Monetaria annulus, the ring cowry, so-called because of the bright orange-colored ring on the back or upper side of the shell, was commonly used as shell money much like Monetaria moneta. Occasionally the ring part on its back would be hammered away, making it nearly indistinguishable from other money cowry species. Many shells of the species were found by Sir Austen Henry Layard in his excavations at Nimrud in 1845–1851. The shell was also introduced to Native Americans during and after the fur trade by European traders as a cheaper substitute  for highly treasured elk ivory, for dowry, and for other uses as ornaments.
Images of shells
Monetaria annulus obvelata may be a Tahitian subspecies
- Monetaria annulus (Linnaeus). WoRMS (2009). Monetaria annulus (Linnaeus). Accessed through the World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=216875 on 10 October 2010.
- Monetaria obvelata (Lamarck, 1810). WoRMS (2011). Monetaria obvelata (Lamarck, 1810). Accessed through the World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=570809 on 20 June 2018.
- Verdcourt, B. (1954). The cowries of the East African Coast (Kenya, Tanganyika, Zanzibar and Pemba). Journal of the East Africa Natural History Society 22(4) 96: 129-144, 17 pls.
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