what is a clam characteristics
1 Clams can control their outer shells and shut them in response to stimuli, via a elastic ligament and two large muscles. 2  In side their usually grey, black shells you can see a white, tan center. 3  Clams have siphons that forces water out and allows them to take in micro organisms. Clams have two shells(Bivalve) that filters their food. 2  Clams can control their outer shells and shut them in response to stimuli, via a elastic ligament and two large muscles. 3  In side their usually grey, black shells you can see a white, tan center.