I have 3 little clowns that have been kept seperate from my main tank with a divider. Came home today and one little guys was in the main section of the tank with a couple of cichlids. Next thing I notice is the clown is back in the divided section and is now missing his dorsal fin and a chunk of flesh from his back. He seems ok, he ate some blood worms but isn't swimming quite right. What's are his chances ? If he pulls through will his fin grow back?