Updated: Oct 15, 2021
Moon snails are a family of small to large-sized predatory sea snails. The shells of the species in this family are mostly round, hence the name moon snails. They are white with undertones of grey, pink, brown, purple, and tan. It has been estimated that worldwide there are about 260 to 270 species of moon snails. These marine gastropods live on sandbars and mudflats, and at a great variety of depths depending on the species.
In winter, moon snails move out into deeper water and come back towards the shore in summer. During the summer they return to their sand bars but in winter they bury themselves in the sand out in deeper water. There they can also continue finding food.
Moon Snails are carnivorous predators that eat mainly the clams that share their habitat. When they find a clam, they grip it in their large foot and drag it off into the sand. They then use their long tongue that has six rows of teeth to drill a hole into the clam's shell, they then excrete an acidic enzyme into the clam's shell to help them digest it. It takes the snail about a day to eat a clam and they will eat one every four days. They will also eat other snails, herring eggs, and most species of mollusks.
For moon snails, summer is the season that they typically mate, during this time the males and females stay separated until they find a mate. Once the female is ready to lay her eggs she will create a sand collar with mucus and surrounding sand. These collars sandwich their eggs between two layers of sand to keep them protected. The collars are somewhat like a flattened clerical collar with a big opening in the center where the baby snails can exit once they are fully developed. This happens over a period of a few weeks. Once they are fully developed they move into deeper water. Adolescent moon snails are herbivores for the first part of their life, eating sea lettuce until they are ready to handle catching and eating clams.
Like most marine snails, the moon snail has a muscular foot that is used to not only move around on the sand but also to plow under the sand’s surface. A moon snail’s foot muscle can grow to be 13 to 14 cm in length, while the shell can be as big as 12 cm. The moon snail’s foot can do something that most snail feet can’t; it can fill with water and expand to an incredible size, almost covering the large shell. Moon snails can live to be 15 years old. If you want to learn more about marine life check out some other articles on the Beachlex site!