Cowrie

Found in shallow waters, in caves, beneath dead corals and under ledges. Their shells are shiny.
They feed nocturnally on carrion, molluscs, seaweed and sponges.

Cypraeidae have beautiful shells and equally beautiful mantles.
The Cowries are probably the most admired and sought after by shell collectors.
Cowries have few predators, but the mollusc-eating cones like Conus textile and octopus can inject venom into the cowry's flesh through a small hole and then sucks out the contents.
The mantle is like a cloak around the shell, highly muscular and when it contracts it forces water through the tubular siphon to propel itself rapidly through the water.