Sea Water Mussel Taken at Uig Sands on 10th July 2009 using  Nikon D40X with Nikon 300 mm zoom lens Sea Water Mussel. Species: Order: Family: Over 52 genera. This one unknown. Mytiloida Mytilidae Food: Habitat: Reproduction: Plankton and other microscopic sea creatures. Are usually found clumping together on wave-washed rocks, each attached to the rock by its byssus. In marine mussels, fertilization occurs outside the body, with a larval stage that drifts for three weeks to six months, before settling on a hard surface as a young mussel.