Giant Helmet Shell

Description:

Also known as Helmet Shells, Giant Cassis Cornuta, Helmet Seashell, Helmet Shell, Giant Horned Helmet Conch, Horned Helmet Shell, Horned Helmet, Hawaiian Helmet Shell and Bonnet Snails. They feed on sea stars -- including the Crown-of-Thorns sea star -- and sea urchins grow to about 22cm in length. Cassidae can grow very large and their shells resemble Roman helmets. These are sand dwellers who hunt sea urchins such as sand dollars, using chemicals to penetrate through the hard case via the anus or by drilling a hole.

Habitat:

Found on sandy bottoms in lagoons buried in the sand during the day and coming out at night to feed on sea stars and sea urchins. Widespread in the Indo-Pacific region.

Notes:

I spotted this shell at a depth of about 25m.