Lewis’ Moon Snail

Neverita lewisii

Lewis’ Moon Snail

Neverita lewisii

Sandy Coast

At the Aquarium

Sandy Coast

Appearance

Like other snails, the Lewis’ Moon Snail has a shell. This shell is spherical and grows to be around 5 inches wide. This snail has a large “foot” that can stretch out to be over 12 inches. The large foot of this snail is often seen partially covering the shell. A Lewis’ moon snail will often weigh just under a pound. This weight is not consistent since the size of its foot can change when inflated with water. When this foot is fully stretched out, water makes up a quarter of its body weight.

Habitat

Sandy and muddy bays and low intertidal zones

Diet

Clams and other shellfish

Life History

During spring and summer Lewis’ moon snails prepare to lay their eggs. These eggs are laid in a gelatinous circular shape called a mucus collar. Once the eggs hatch they stay in the collar for safety. After a few weeks, over 500,000 juveniles emerge from the mucus collar. Instead of feeding on clams and other shellfish, juvenile Lewis’ moon snails feed on a type of phytoplankton known as diatoms and a seaweed known as sea lettuce. After about six months these juvenile Lewis’ moon snails stay on the sandy sea floor and begin hunting for shellfish.

IUCN Status

Not Evaluated

Ecosystem & Cultural Importance

Despite eating the same clams that people harvest, the amount that Lewis’ moon snails eat is not enough to significantly impact the claming industry. The shell of the Lewis’ moon snail is often used by larger hermit crab species. In California there is a limited harvest of Lewis’ moon snail. These snails once harvested can provide a meal to those that harvested them.

Northern Mexico to southern Canada

The Lewis’ moon snail can be found in waters along the Oregon Coast. When exploring Oregon’s sandy shores and bays, you might be lucky enough to spot this special snail.

The Lewis’ moon snail zig zags across the sand, using its sense of smell to find its favorite food: shellfish.
Snails eat using a radula, a tongue-like organ covered in thousands of tiny teeth. While shellfish, such as clams, have a tough outer shell, the Lewis’ moon snail can break in by climbing atop their prey and using their radula to drill an access hole to reach the meat inside.

Citations & Other Resources

Cook N., L. Young. 2010. Determining the Ecological Role of Euspira lewisii: Part I: Feeding Ecology. Journal of SHellfish Research 29(1):223-232
Morris, R. H., A. P. Donald, H. C. Eugene. 1990. Intertidal Invertebrates of California. Stanford University Press, Stanford, CA, USA.
Encyclopedia of Puget Sound. 2024. Polinices lewisii. University of Washington. https://www.eopugetsound.org/species/polinices-lewisii

Lewis’ Moon Snail

Lewis’ Moon Snail

At the Aquarium

Appearance

Habitat

Diet

Life History

IUCN Status

Ecosystem & Cultural Importance

Citations & Other Resources

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