Geoducks: The biggest clam of all...

And it is pronounced gooey-duck.  Well they are big but not bigger than these guys (which can weight hundreds of pounds), but the geoduck is the biggest clam in North America.  They can be three feet long.  For some reason they are prized delicacies in Asian markets (can you guess why):

Is that a geoduck in your pocket or are you just glad to see me?

They are actually delicious.  In China the syphon is the most prized part (it is crunchy and fibrous), but the most tender and tasty meat is the ribbon of mussel inside the shell.  Here is a recipe.

And given that these clams can sell for $100 each, there is a thriving black market in geoducks.