Panopea generosa, more commonly known as the Pacific geoduck, is the world's largest burrowing clam. With a small shell and very long siphon, or neck, geoducks are found along the West Coast of the United States. There is both a wild harvest and a growing geoduck aquaculture industry, particularly in Washington State. The majority of Washington's geoduck farming takes place in southern Puget Sound. Geoducks live long lives, with the oldest geoduck recorded at 168 years old. These clams burrow into the sediment about one foot per year, to a depth of three feet. In the first three to five years of life, geoducks grow to 1.5 pounds, though they may not reach the maximum size of approximately 7 pounds for 15 years. Female geoducks release between 1 and 2 million eggs per spawn. 

Panopea generosa, or Pacific geoduck, is designated as the official clam of the state of Washington. 

PRO: The geoduck is great. It is the largest burrowing clam in the world and can live up to 168 years. Geoducks clean the water as they live and that's pretty cool.