Watch them lobsters around anything...... Their gluttony can wreak havoc.... Have watched one decimate 5 stinging anemones in one week.... They seem immune to the sting and dig food from within the anemone, with fatal damage. W.r.t. it attacking the clam..... It is possible, very possible.,,,Or should I say probable. Once it has grown..... who knows, you might get away with it......... Until the clam shows signs of weekness......