Oh hey, not to be one of *those* people but I looked this up because I was shocked I had never heard of clams' tongues before. Ends up that that isn't his tongue. It's actually his foot. He's just feeling around his new habitat. Clams filter water for food particles so they actually don't have tongues. Doesn't make this any less weird of a clam gif though.
That clam is using it's "tongue" (actually it's foot) to try and move around as it would in the ocean. From what I've heard the salt is actually harmful, its like salting a slug.
*clam places foot on hand*
AWWWWWWWW I WANT ONE