Cypraeidae have adult shells which are very rounded, almost like an egg; they do not look like a typical gastropod shell. Their glossy, polished, ovate-shaped shells have beautiful patterns in a variety of colors. These patterns, combined with minor variations in shell form, have led some conchologists to recognize 60 genera and hundreds of species and subspecies.
In virtually all of the species in the family Cypraeidae, the shells are extremely smooth and shiny. This is because in the living animal, the shell is nearly always fully covered with the mantle.
The upper surface is typically convex, while the ventral side is flattened. Typically, no spire is visible in the fully adult shell. There is a long, narrow, aperture that runs along the length of the ventral side. The aperture is lined with "teeth".
Juvenile cowry shells are not at all similar to adult cowry shells. The juvenile shells of cowries perhaps more closely resemble the shells of some "bubble snails" in the order Cephalaspidea. Also the shells of juvenile cowries seldom exhibit the same color patterns as the adult shells do, and thus can be hard to identify to species.
The Cypraeidae constitute one of the most widely distributed groups of gastropods in tropical and subtropical seas. The cowries are one of the most abundant and diversified groups of shells to be found on reefs and rocky intertidal flats and sandy substrates in the island area.
Predators and preyedit
The very narrow toothed aperture of the cowry shell makes the adult shells difficult for many predators to reach into. However cowries are still vulnerable to predation:[2]
Some mollusc-eating cones, such as Conus textile, can inject venom into the cowry's flesh. The cone then extends its stomach into the shell, through the aperture, to completely ingest the flesh.
Some octopuses can gouge a small hole (using a special barb/tooth and an acidic secretion) through the shell to inject a venom that kills the animal within.
The eating habits of cowries are poorly known, because most species are nocturnal and cryptic, but sponges are the most commonly described prey. Off the coasts of Australia, common cowry species eat sponges,[2] and on Caribbean coral reefs they are known to eat sponges that are otherwise chemically defended against other predators.[3]
Taxonomyedit
For nearly 200 years, every species in the family Cypraeidae was placed in one genus, Cypraea, but in 2002 [4] the cowries were divided into many different genera.
^Lorenz F. 2002. New Worldwide Cowries. Descriptions of new taxa and revisions of selected groups of living Cypraeidae (Mollusca: Gastropoda). Schriften zur Malakozoologie aus dem Haus der Natur-Cismar 20: 1-292, pl. 1-40
^ abcdeMeyer C. P. (2003) "Molecular systematics of cowries (Gastropoda: Cypraeidae) and diversification patterns in the tropics". Biological Journal of the Linnean Society79(3): 401–459. doi:10.1046/j.1095-8312.2003.00197.x
Meyer, Christopher P. (2004). "Toward Comprehensiveness : Increased molecular sampling within Cypraeidae and its phylogenetic implications" (PDF). Malacologia. 46 (1): 127–156. Archived from the original (PDF) on 2011-05-14. Retrieved 2010-10-10.
Felix Lorenz and Alex Hubert : A Guide to Worldwide Cowries, second revised edition, Conch Books, 2002 ISBN 3-925919-25-2
Lorenz F. (2017). Cowries. A guide to the gastropod family Cypraeidae. Volume 1, Biology and systematics. Harxheim: ConchBooks. 644 pp.
External linksedit
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