Once buried, a geoduck's shell remains sedentary. While other clams move to avoid predators, a geoduck, when approached by a hungry crab or spiny dogfish, retracts its siphon, like a turtle ...

At first sight, the moon clam may not look like a contender for stardom. Its size is humble, its color pale. Most shocking of all, for a clam, its shells can’t even close. But this oddball of the ...