Moon Snails (Euspira lewisii) are an intertidal invertebrate well known for their large size (up to 11 inches). Moon Snails are voracious predators of clams that share their intertidal habitats.
When they find a clam they often drag it farther into the sand and envelop them in their big foot. A gland on their proboscis secretes enzymes that helps the radula with seven rows of teeth to burrow a hole into the Clam shell. The Moon Snail then sucks the Clam tissues out of the shell over a period of days. Feeding on clams results in an accumulation of poisons in the Moon Snail that can cause paralytic shellfish poisoning to humans if eaten.
Moon Snails are large enough that they do not have many predators except for the occasional Sunflower Star attack. Moon snails move into deeper water in the winter and back toward the shore in the summer to breed.
Photo and caption by Coastal Programs Coordinator, Casey Cruikshank.