Cassis
Cassis is a genus of large, predatory sea snails, marine gastropod mollusks in the family Cassidae, the helmet shells. They are commonly called “helmet shells” due to their hard, helmet-like shells. They are known for their beautiful, often intricately patterned shells. There are about 20 species within the genus Cassis.
Common Names
Cassis species are commonly known as helmet shells, but other names are used for particular species, such as:
- The "Florida helmet" (Cassis flammea)
- The "Giant Helmet" (Cassis madagascariensis)
- The "Queen Conch" (Cassis tuberosa)
Characteristics
Members of the genus Cassis are distinguished by their large, thick, heavy shells. The shells have a distinctive shape, resembling a helmet or a human head. They usually display a wide aperture, a distinctive spire, and a prominent siphonal canal. The exterior surface often features intricate patterns, including spiral ridges, knobs, and bumps. The shell color varies greatly among species, ranging from creamy white to brown, orange, and even black. The shell is often adorned with bright, bold patterns. The mantle of Cassis species is often brightly colored and patterned as well, with some species exhibiting bioluminescence.
Environment
Cassis species inhabit tropical and subtropical waters worldwide. They prefer sandy or muddy bottoms in shallow water, usually near coral reefs or rocky shores. They are primarily found in the Indo-Pacific and Atlantic Oceans, ranging from the Caribbean Sea to the Red Sea. Cassis are active predators, feeding primarily on echinoderms such as sea stars and sea urchins.