<sod>A striking feature of molluscs is the use of the same organ for multiple functions. For example, the heart and [[nephridia]] ("kidneys") are important parts of the reproductive system, as well as the circulatory and excretory systems; in bivalves, the [[gill]]s both "breathe" and produce a water current in the mantle cavity, which is important for excretion and reproduction. In reproduction, molluscs may change gender to accommodate the other breeding partner.<eod>
<sod>A striking feature of molluscs is the use of the same organ for multiple functions. For example, the heart and [[nephridia]] ("kidneys") are important parts of the reproductive system, as well as the circulatory and excretory systems; in bivalves, the [[gill]]s both "breathe" and produce a water current in the mantle cavity, which is important for excretion and reproduction. In reproduction, molluscs may change sex to accommodate the other breeding partner.<eod>