Pinacocytes line the incurrent canals and spongocoel. Incurrent and excurrent siphons directed upwards, away from substratum. A mussel draws water in through its incurrent siphon. Each clam then fills its water chambers and closes the incurrent syphon. They pump water through the incurrent aperture, obtaining oxygen and food. There is an inhalant or incurrent siphon, and an exhalant or excurrent siphon. "Fusconaia flava" males release sperm and the females collect the sperm through the incurrent siphon.