Swan Mussel

The swan mussel belongs to a group of mollusks known as bivalves *(Bivalvia)*, characterized by a body encased in two shells. These shells are held tightly together by adductor muscles, which close the shell, while an elastic ligament allows them to open without energy expenditure. This is why dead mussels are often found with open shells, because the adductor muscles have ceased to function. The swan mussel obtains food and oxygen through a water flow that enters the body cavity via the incurrent siphon located at the rear. Water flows over the gills, where it is oxygenated and filtered for tiny food particles. These particles are trapped by the gills, bound together with mucus, and transported by cilia to the mussel's mouth. The digestive system consists of a mouth, pharynx, stomach with a digestive gland (hepatopancreas), and an intestine that empties through the excurrent siphon. The swan mussel has an open circulatory system with a heart encased in the pericardium, which is connected to a pair of kidneys. Its nervous system is simple, consisting of three ganglia. Swan mussels are gonochoristic, meaning individuals are either male or female. They have a larval stage called a glochidium, which initially develops on the parent's gills but later parasitizes the skin or gills of fish.