Bulla

Bulla is a genus of sea snails, marine gastropod mollusks in the family Bullidae. These snails are characterized by their inflated, often fragile, shells that are coiled but largely hidden within the animal's mantle. The shell is typically smooth and ovate, though its appearance can vary somewhat between species. Bulla species are found in tropical and subtropical waters worldwide, inhabiting sandy or muddy substrates in shallow coastal areas, estuaries, and sometimes deeper marine environments.

The anatomy of a bulla snail is notable for the large, fleshy mantle that covers most of its shell. This mantle can be extended and is used for locomotion, burrowing, and defense. Bulla snails are generally herbivores or detritivores, feeding on algae, sea grass, or organic matter found in the sediment. They are often crepuscular or nocturnal, becoming more active during dawn and dusk or at night. Reproduction typically involves external fertilization, with females laying masses of gelatinous eggs. The larval stage is planktonic, aiding in dispersal. Some species may produce defensive secretions to deter predators. Common examples include the Atlantic bulla and the brown bulla.