The highly decorated shell of the Cypraea is much prized by collectors. In aquariums
the porcelain-like shell is only visible when the mollusk is at rest; when they
are active, it is covered by the mantle (the most external part of the body), containing
the sensitive organs. Two species are sometimes found on the market, both with a
carnivorous tendency: the tiger Cypraea (Cypraea tigris), over 10 cm in length,
and the geographical Cypraea (C. mappa), which rarely exceeds 7 cm. They are mainly
active at night.