Have a close look at the picture on the left. The broken ceramic bowl on the beach is actually not a bowl! It is the egg mass of the Moon Snail. The snail lays its eggs pressed together with sand particles held together with a mucous. The collar is quite flexible, almost feels like its made of rubber with sand particles mixed in.
About half way through the summer, the eggs hatch and the collars fall apart. The free swimming snail larvae become part of the zooplankton in the ocean until they are ready to settle down and transform into little moon snails. You can see that the egg collar reflects the size of the snail that laid it.
So how do you think the other shell in the upper right hand corner got the hole in it? The moon snail made that too! The moon snail uses its radula, or sand-paper-like tongue, to drill a small hole near the hinge of the clam. Then it sucks outs the contents. Many different types of snails that share this behavior are commonly known as "drills".
The actual snail is much larger than the shell and often when mature, they cannot pull themselves all the way back in. To protect themselves, and during their search for food, they dig deep through the sand and muddy beaches at the low intertidal zone of protected beaches where they spend much of their time. This is why most people see only the shells and not the live animals.
The snail is one of the largest found on the west coast and reaches sizes of up to 12cm (4.5 inches). Moon snails are members of the 'gastropod' family which means 'stomach-foot'. They are related to freshwater snails, squid and octapi.
Please do not disturb the live snails if you find them and leave the shells and egg cases where you find them (take only pictures) as they have an important role in nature and are recycled by the waves into homes for other creatures or to add calcium and other minerals back to the water.
by Donna Hill B.Sc. B.Ed. 2004
Would you like to see moon snails and other intertidal beach creatures in person? Check out our
At the Edge: Marine Intertidal training program and other nature training in Nanaimo, BC.