Pododesmus macroschisma

How to Distinguish from Similar Species: There is no other local species similar to this. Oysters cement one shell to the substrate but they are much larger, have thick shells, and do not have the hole in the shell through which a byssus attaches. The rock scallop Hinnites gigantea is larger, has a thicker shell with no hole in it, and has a deep purple stain on the inside of the shell near the hinge.

Biology/Natural History: Predators include the seastars Evasterias troschelii and Orthasterias koehleri. Dead shells of this species are often colonized by boring sponges such as Cliona celata var californiana. The name "jingle shell" comes from the fact that the dead shells make a pleasant jingling sound when struck together. People often make mobile chimes from them, using the handy byssal hole to hang them. Pododesmus macrochisma is now an Alaskan species, different from this species.

Cemented to rocks, plastic, or wood. Common on pilings

Geographical Range: Bering Sea, Alaska to Baja California; Chukchi Sea

Depth Range: Low intertidal to 90 m

This unique bivalve species has thin valves, nearly circular in outline. The right valve is permanently cemented to the substrate. The right valve has a large hole in it near the hinge, through which byssal material cements the bivalve to the rock. The left valve has a dark muscle scar opposite the perforation in the right shell, and is otherwise polished inside and often bright iridescent green. Flesh is bright orange. Diameter to 10 cm.