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Land invertebrates

Slugs and snails

Common garden snailCommon garden snail Slugs and snails are gastropods, a group of molluscs with soft bodies that move about on one large foot. They move by alternately shortening then stretching their bodies. Slugs and snails have two pairs of feelers, called tentacles, on their heads: one pair for seeing and one for touch and smell. Most species feed on leaves and fungi. Unlike slugs, snails have hard shells. Snails will withdraw into their coiled shell if they are attacked.

Powelliphanta annectens, from New ZealandPowelliphanta annectens, from New Zealand

Gastropod species

Different species of gastropods are found both on land (terrestrial snails) and the sea (sea snails)—including at the bottom of the deep ocean. There may be up to 100,000 living species of snail and slug, including about 24,000 known terrestrial species, 30,000 known marine species and about 5000 known freshwater aquatic species.

Shell of the Roman snailShell of the Roman snail


The word gastropod comes from the ancient Greek words gaster, meaning "stomach", and pod, meaning "foot". It was once thought that snails crawled around on their bellies.

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