snail

Snail is a common name for many species of air-breathing land snails and their aquatic relatives, all of which are mollusks within the class Gastropoda. Most have a single, spirally coiled shell into which the body can retreat. A broad, flat muscular foot powers locomotion, and the mantle secretes the shell and houses the animal's organs. In terrestrial species, the mantle cavity acts as a lung; in many aquatic snails it functions as a gill. The radula, a ribbon-like structure with tiny teeth, is used to feed on plants, algae, or detritus.

Snails occupy a wide range of habitats worldwide, from forests and grasslands to freshwater and marine environments. They vary greatly in size, shape, and shell sculpture. Diet is primarily vegetal, including leaves, stems, and decaying matter, but some species feed on fungi, bacteria, or animal matter. Moisture is essential for most snails, which limits their distribution in dry habitats.

Most snail species reproduce sexually; many terrestrial species are hermaphroditic and copulate with other individuals, while some aquatic species have separate sexes. Eggs are typically laid in damp soil or water and hatch into juveniles that resemble small adults. Growth is slow, and lifespans range from a year to several years in many species.

Snails play important ecological roles as decomposers and as prey for a wide range of animals. They are also valued as a food source in some cultures and can be agricultural pests in others. Conservation concerns include habitat loss, pollution, and climate change; some freshwater and land snail species are threatened or endangered.