Nuttallia obscurata

Nuttallia obscurata, common name the "purple mahogany clam", "dark mahogany clam", "varnish clam", or "savory clam", is a species of saltwater clam, a marine bivalve mollusk in the family Psammobiidae. This clam is native to Japan. It has been introduced in the North American coasts of the Eastern Pacific Ocean, in British Columbia, Washington and Oregon, where it is considered to be an invasive species; it is often harvested for food there.

A 2006 study of reproductive ecology and dispersal potential suggested that a "lengthy planktonic phase, combined with favourable oceanographic circulation patterns, has contributed to the rapid dispersal and geographic range expansion of the varnish clam in the Northeast Pacific."