Cassis madagascariensis, common name the queen helmet, is a marine gastropod mollusc in the family Cassidae, the helmet shells and bonnet shells.It is known for being the largest species of its family in the Atlantic Ocean. This organism has 4 direct children, which include Cassis madagascariensis f. spinella Clench, Cassis madagascariensis spinella Clench, Cassis madagascariensis var. major Rigacci, and Cassis madagascariensis var. minor Rigacci.

Distribution

This species occurs in the tropical Western Atlantic, the Gulf of Mexico and the Caribbean Sea. The specific name "madagascarensis" literally means "of Madagascar", but this was a misunderstanding of the type locality by the original author.

Description

The maximum recorded shell length is 409 mm. The organism does not have a vertebrae. Has a large and heavy shell, with a short spire. This shell typically has three rows of blunt knobs and smaller lines of spiral folds. It has an elongated aperture with folds on both sides of the inner aperture. This shell can vary in color from white to tan and sometimes has brown markings and blotches.

Habitat

United States Virgin Islands, St. John. Emperor/Queen Helmet Snails frequently observed (photographed) in depths as shallow as two feet. This contradicts the previously reported minimum depth of 3 m. The maximum recorded depth is 183 m.

Human uses

Shells of Cassis madagascariensis are used in jewellery to make cameos. In the Maldives the shell is boiled and the boiled water of the shell is used as a traditional remedy for Flu and fever like symptoms.