moon snail
Polinices lewisii
Description: Large white to tan shell, with enormous translucent pink to brown foot. The snail pumps water into its mantle and foot, increasing its mass to 3 or 4 times that of just the shell alone. When threatened, the snail pumps the water out of its body, pulling entirely inside the shell, and sealing the shell with a brown door-like operculum. Common in sandy and rocky intertidal. Up to 5.5 in (14 cm) high.
Food: This snail is one of the top predators of the intertidal environment. Chief among the moon snail's preferred foods are clams. The snail surrounds the clam with its foot, then drills into the clam shell with a radula, which is covered in tooth-like rasps. Weak acids also are excreted onto the shell, hastening the drilling process. Once the characteristic hole is made, near the clam's hinge, the snail injects digestive enzymes into the clam. When ready, the snail scrapes and sucks out the meat from the clam, leaving an empty clam shell behind. An adult moon snail can eat a clam every 4 days.
Reproduction: Female lays eggs in distinctive round molded sand collar. Made of a layer of sand, then a layer of tiny eggs, and then another layer of sand, the whole egg collar is held together with snail mucus. Eggs are laid in spring through fall, and the 500,000 eggs in each collar hatch out in about 6 weeks.
Fun Facts: Besides humans, gulls are the chief predators of the moon snail. A gull will pick up a snail and carry it aloft, and then drop it onto the rocks to break open the shell.