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What do Snails Eat?

Have you seen a snail sliding along a sidewalk on its muscular foot? Snails are fascinating invertebrates that carry their home, a spiral shell, with them as they move. Their shell provides them support and protects them from predators.

Snails can be found all over the world in deserts, forests, rivers, lakes, oceans, gardens, and even in artic climates. They are classified in the phylum Mollusca —which they share with octopuses, clams, and other types of soft-bodied invertebrates—and class Gastropoda, which they share with slugs. The word gastropod comes from Greek and means “stomach foot.” The foot of the snail is used for movement and support, and it lies under its belly, hence its name.

Table of Contents

How do snails eat?

Snails have a unique tongue-like structure called a radula. In Latin, radula means “little scraper.” The radula is lined with thousands of microscopic teeth which scrape and tear food as the snail moves over the food.

Snails are heterotrophs, which means that they eat other plants or animals for their energy and nutrients. Snails can be placed into four groups of heterotrophs based on what food they consume. These groups are detritivores, herbivores, carnivores, and omnivores.

Snails that are detritivores

Terrestrial snails that are detritivores (decomposers) consume food that you may see in a yard, for example, lawn clippings, branches, sawdust, moss, and leaves. Manure, sludge, dead animals, and insects may also be a meal.

Snails that are carnivores

Aquatic carnivorous snails will prey on small shrimp, starfish, worms, insects, and other snails. An example of a carnivorous snail is in the moon snail (Family: Naticidae). This predator attaches to a clam and releases hydrochloric acid and enzymes to soften the prey’s shell. Once the shell is softened, it uses its radula to form a hole and get inside to eat the meat. Moon snails are also cannibals and will eat other moon snails.

Carnivorous land snails get their energy from slugs, earthworms, insect larvae, and insect eggs. The carnivorous Powelliphanta snail is found New Zealand where it eats slugs and grows as big as a fist.

White-lipped snail (Cepaea hortensis), Cumnor Hill, Oxford. Attribution
White-lipped snail (Cepaea hortensis), Cumnor Hill, Oxford. Attribution, Credit: Wikimedia/Charles J. Sharp

Snails that are herbivores

Aquatic snails that are herbivores consume algae and water plants. If you find holes in a water lily, a snail may be eating it for sustenance.

The diet of an herbivorous snail that lives on land consists of garden veggies like cabbage, cucumbers, spinach, kale, berries, and other fruits. They can be seen eating bark and mushrooms.

Snails that are omnivores

Aquatic snails that are omnivores can be found skimming along and eating small dead fish and insects, duckweed, decaying plants, algae, and water lettuce.

Omnivorous snails living on land eat dead animals, worms, and other snails as well as leaves, vegetables, and flowers. They can quickly decimate garden crops.

All the snails need calcium

Snails require calcium to build strong, protective shells. Without calcium, their shells are brittle and prone to breakage. To grow a larger shell, the snail will secrete calcium carbonate through its skin. When a snail hatches, it must find foods that contain calcium to successfully grow and survive.

Glossary

Invertebrate: an animal without a backbone

Heterotrophs: organisms that eat other plants or animals for energy and nutrients

Herbivores: organisms that feed on plants

Detritivores: organisms that feed on dead and decomposing organic matter

Carnivores: organisms that eat meat, or the flesh of animals

Omnivores: organisms that consume plants, animals, algae, and/or fungi

Radula: a structure that mollusks use for feeding that is similar to a tongue and covered with microscopic teeth

Calcium: the fifth most abundant metal in the Earth’s crust. Calcium is essential to all living things, particularly for the growth of healthy teeth and bones.

Terrestrial: living on the land

Aquatic: living in or near water

Hydrochloric acid: a strongly corrosive acid

Enzyme: a biological catalyst that speeds up the rate of a chemical reaction

Cannibal: an organism that eats another member of the same species

Sustenance: nourishment supporting life, such as food and water

Calcium carbonate: a non-toxic and odorless compound commonly found as a white mineral which occurs naturally in chalk, limestone, and marble

Readability: 65.6

Flesch Kincaid Grade Level: 7.3

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Banerji, Urvija. The Seemingly Innocuous Conus is in Fact a Venomous Killing Machine. May 16, 2016. https://www.atlasobscura.com/articles/watch-a-sea-snail-swallow-a-fish-whole

Thomas, Bob. Carnivorous Marine Snails. July 15, 2007. https://lucec.loyno.edu/natural-history-writings/carnivorous-marine-snails

Nordsieck, Robert. The Living World of Mollusks. https://www.molluscs.at/gastropoda/index.html?/gastropoda/morphology/nutrition2.html

What Do Water Snails Eat—Aquatic Snail Feeding Guide. https://www.totalreptile.com/what-do-water-snails-eat/