Cockles have a soft body which is protected from predation, desiccation and wave movement by a sturdy shell.

If a cockle lives in the intertidal zone it is protected against desiccation by the shell closing tightly together (the adductor muscles do this).

A small amount of water is stored inside the shell, keeping the cockles body moist.

The flatworm Curtuteria australis is a parasite that infects cockles, demobilising them so that they are more easily eaten by oystercatchers.

Once the larvae have been ingested by the birds, they lay eggs, which are excreted and consumed by whelks, who in turn are a food source for cockles.