Paralytic shellfish poisoning is caused from the ingestion of toxin-contaminated bivalve shellfish and crustaceans. Algal blooms of dinoflagellates, usually during the warmer months of June to October, result in toxin accumulation in filter feeders such as bivalves. The most common fish species affected are clams; mussels; whelks, moon-shells and dogwinkles; oysters; whole scallops; crabs and lobster hepatopancreas (tomalley). Toxin bioaccumulates in specific tissues, and can persist for long periods in certain species of shellfish. Butter clams for instance, may retain toxin for up to one year after a toxin producing algal bloom (the latin name for butter clams is Saxidomus, the origin of the name saxitoxin). Toxin accumulates in the siphon, neck and gills in butterclams – it is recommended these be removed and discarded before eating. DO NOT feed these parts to your pets. Sea otter deaths have been linked to butter clams in Alaska.