Most people think of clams as a gooey blob inside of a two-piece shell, but there’s actually a lot more going on inside that shell that you might come to expect.
While it’s true that a clam is rather gooey and that it resides in a two-piece shell, that little blob is actually chock-full of surprises. One of the first things you may not know is that clams have a physical foot that they can extend out their shell to ‘push’ themselves along the seafloor and burrow more than two feet underground. No, it doesn’t look anything like your foot or mine… but it serves practically the same purpose for the clam: transportation.
Another interesting thing inside the clam’s shell is a pair of muscles that clamp the shell shut. These muscles relax or contract, depending on whether the clam wants the shell open or closed. It may open its shell to ‘walk’ along the seafloor, but if it feels threatened, it can contract those muscles so tensely that you won’t even be able to open a clam shell with your two bare hands. Instead, opening a clam shell requires physically cutting into the crack and slicing those muscles.
Clams also exhibit a feature known as the siphon, which looks and behaves a lot like two straws wrapped together. One pulls in water and nutrients from the clam’s surroundings, while the other expels waste produced by the intake. Some clams have very small siphons, and others are so large they don’t even fit inside of the shell. Supermassive clams may also have siphons, or they’ll just open their shells to eat what’s around them.
Intriguingly, some clams may also produce pearls – just like oysters. These pearls are used to trap contaminants that enter the clam’s shell, and they’re just as collectible as their oysters’ counterparts.