Question: what are siphons in clams?
Answer: Siphons in molluscs are tube-like structures in which water flows (or more rarely in which air flows). ... The siphon is part of the mantle of the mollusc, and the water flow is directed to (or from) the mantle cavity. A single siphon occurs in some gastropods. In those bivalves which have siphons, the siphons are paired.