Adult males and females are ectoparasitic on marine and freshwater fish. They may occur within the gill chambers or on the body surface. Both sexes may leave the host from time to time and swim, reattaching later. The female leaves to deposit eggs at the bottom of the water. Eggs hatch in a few weeks, releasing a copepodid larva. The copepodid molts several times until it reaches the adult form, then swims to find a host.