Saxidomus giganteus, or the butter clam, is a bivalve mollusk of the family Veneridae occuring along the Pacific coastline of North America from California to Alaska. Its shell measures on average three inches in length with light grey and white coloration and smooth ridges; inside its flesh is totally white. The butter clam can be found in the intertidal zone, usually buried to a depth of approximately one foot in sandy, gravelly, and mixed-shell substrate. Like most bivalves, it lives a sedentary lifestyle filter-feeding and consuming a diet of phyto-plankton. Unlike most bivalves, it has the ability to sequester paralytic shellfish poisons (PSTs) in its siphon and store them there for as long as two years, deterring any siphon-nipping predator. The butter clam is used for a variety of purposes, ranging from archaeological research to monitoring water pollution.