Ryan Photographic - Ovulidae - False cowries

Family Ovulidae

The ovulids are a widely distributed family of gastropod molluscs. Mostly tropical, some are found in temperate waters. They are all (or nearly all) carnivores on soft corals and seafans and in many cases closely mimic their hosts. The precise color matching comes from ingesting the same compounds that produce their host color as they feast on their host polyps. It is their mantle that produces the match, the shells are usually monchromatic in shades of cream. The egg cowries tend to have a "typical" cowrie shape but the spindle cowries are elongate which gives them their common name. The mantle of some of the spindle cowries even produces filaments that match the tentacles of the polyps on which they feed.

The first spindle cowrie I ever photographed (below) had eaten an area of polyps from its host seafan leaving a white skeleton behind. It was this area of white, rather than the cowrie, which attracted me and I didn't immediately see the animal.

The common egg cowrie has a black mantle and is "reluctant" to retract it. As a result, it looks more like a giant sea slug than a cowrie.

Aclyvola species

Cyphoma gibbosum Flamingo tongue snail

Cyphoma gibbosum Flamingo tongue snails, Bahamas

MOLL 3130 Cyphoma gibbosum Flamingo tongue snail, Belize.

Dentiovula dorsuosa Violet egg cowrie

Hiatavolva coarctata Compressed cowrie

Margovula marginata Margined egg cowrie

Ovula ovum Egg cowrie

Phenacovolva birostris Double-snouted spindle cowrie

Gastropoda

 Photo Library