Money Cowrie Snail - Cypraea moneta

The Money Cowrie Snail (Cypraea moneta) is highly variable in appearance. The shell can range from white to tan and may have an oval or more kite-like shape.

Cowrie Snails are well known to shell collectors for their attractive shells and are popular among aquarists for algae control. They look like oval-shaped domes in appearance, much like the top half of a football (the American kind). Their shells are usually very shiny and have a "polished" appearance, due in large part to the fact that the shell is usually covered and protected by the animal's mantle. This mantle may be similar to the coloration of the shell or may be very different from it, depending on the species. The mantle and animal extend from a slit-like opening on the underside of the shell instead of a round opening like other snails.

Cowries are algae eaters and grazers. They need plenty of algae to graze on, both tiny microalgae and larger macroalgaes, including "nuisance algae" like the filamented hair algae that plague some aquariums. None of the true cowries (those from the genus Cypraea) prey on corals or other animals, but there are some very closely related snails that do prey on gorgonians and other soft corals (those from the genuses Cyphoma and Ovula are most common in the aquarium trade).

While cowries are safe for reef aquariums in that they will not eat corals, polyps or other similar invertebrates, some do get rather large. With this size comes a certain amount of clumsiness and they may topple corals or rockwork as they move, causing some physical damage on their way.