Cassidae

Cassidae, commonly known as helmet shells or bonnet shells, are a family of large, heavy sea snails, marine gastropod molluscs in the superfamily Tonnoidea. These snails are characterized by their thick, heavy shells, often with a distinctive helmet-like shape. They are found in tropical and subtropical waters worldwide, often inhabiting rocky reefs and sandy bottoms.

Scotch Bonnet – Semicassis granulata

Semicassis saburon

Casmaria unicolor

Cypraecassis tenuis

Cassis fimbriata

Horned Helmet ,Giant Helmet, Helmet Shell – Cassis cornuta

Heavy Bonnet Snail – Casmaria ponderosa

Common Names

Cassidae are commonly known as helmet shells or bonnet shells due to the shape of their shells. They are also sometimes called "cassid snails" or "helmet snails."

Characteristics

Cassidae are characterized by the following features:

  • Shell: Thick, heavy, and often with a helmet-like shape. The aperture is wide and often has a distinctive lip or callus.
  • Size: Cassidae are generally large, with some species reaching lengths of over 15 cm.
  • Color: Shell coloration varies widely, with some species exhibiting bright colors and patterns, while others are more muted.
  • Operculum: Most cassid snails have a horny operculum, a protective plate that covers the aperture when the animal retracts into its shell.
  • Lifestyle: Cassidae are carnivorous, feeding primarily on starfish, sea urchins, and other echinoderms.

Environments

Cassidae are found in tropical and subtropical waters worldwide. They typically inhabit rocky reefs, sandy bottoms, and seagrass beds. They are often found in shallow waters, but some species can live at depths of up to 100 meters.

References

For further information on Cassidae, refer to these reliable sources: