What kind of information do you want? Whether it will heal or how to catch a fish? It seems like your looking for someone to tell you that everything is going to be ok, but its not. Clams can heal themselves given time if they are not injured too badly. If a fish has taken a liking to clam and you don't remove it or protect it somehow, it will die as it will not have anywhere near enough time to heal. I have a juvenile T. Maxima that got nibbled, not by a predator but by a fish who saw it as encroaching on its territory. After moving it the nibbling stopped. Its been a month since then at least and its only grown back about 90% of a very small amount of damage. In your situation it sounds like either the fish or the clam has to go and in its current injured state, moving the clam might seriously reduce its chances of surviving.