Project Description
Gastropods
Periwinkles, Conchs, Turbans, Limpets
Of the seven major groups of mollusks, the largest is the class Gastropoda commonly called snails. The name Gastropoda literally means “stomach-foot.”
Anatomy of a Gastropod
What snails eat
Many snails, like the ones you may find in your garden, are vegetarians and feed on plants and algae. Some snails are predators and eat other invertebrate animals, often other snails.
Snails don’t have teeth like you do
Snails have a rasp-like ribbon of sharp teeth called a radula that they use to get food. Radulae are used to scrape algae off rocks or even drill holes in the shells of other mollusks. In some snails the radula is shaped like a harpoon and is used to spear fish.
Snails are always at home
Snail shells are made by the individual snail and grow as the snail grows larger. Although most snails have a coiled shell, many shells are flat or saucer-shaped and are often very shiny and colorful. Some snails have no shells at all, like the brightly colored sea slugs.
In addition to their shells some snails have an operculum, or trap door, that can be used to close up the opening of the shell to protect the snail from predators or from drying out if the snail is out of the water.
Snails have adapted to aquatic and terrestrial environments
Most snails live in the water, and like fishes, use gills to get the oxygen they need. Land snails have evolved a kind of lung that allows them to breathe air.
Snails have eyes
Snails often have two large eyes attached to stalks on their heads. Many snails use a siphon to smell their surroundings and locate food.
Snails are twisted
Snails are twisted: Evolutionarily the bodies of snails have undergone a process called torsion which involves the rotation and twisting of the snails internal organs.
Snails need our help
In the United States, many of our freshwater snails are threatened by pollution and destruction of habitat. Scientists are beginning to investigate the effects of human impacts on land snails too.
