fish disapearing

Question
I have a 55gal.tank.In it have large algee eater,tiger,two mollies and a rather small blue lobster.When changing water today, noticed two Mollies gone!Not a sign of them,or remains!
(forgot to mention a tiny neon)With the fish i listed, is it possible one of them is killing and eating the others? What about the lobster?
I would greatly appreciate any insight you might have concerning my problem.
Thank you for your attention.
Sincerely,
Rick

Answer
Hi Rick,
It is possible that the lobster killed the mollies.  Prawns and lobster in a tank is risky.  Any fish that swim close within its reach will be snagged.  Unless they are hiding and you cannot see them, or they jumped out.  But I would bet the lobster is the culprit.
-Matt-