The molluscan bivalve, Anomia simplex, or the jingle shell attach themselves to hard objects in the water--often other shells--by means of byssal threads that extend from a hole in the lower valve. Their shape is often influenced by the shape of the object they are attached to. The upper valve is concave, while the lower is flatter. In the image above, the jingle shells are the light colored, translucent shells on the surface of the mussel's shell. Click on the image for a larger view.

Jingle shells have separate male and female individuals. Fertilization occurs within the mantle cavity and young hatch as pelagic larvae. In general, jingle shells feed on planktonic and tiny detrital food items through filter feeding.