We have a sick Panther Grouper. He has been in our 55 FOWL tank for about a week now showing no signs of stress and eating like a pig. I have noticed that he has been eyeing our Pistol Shrimp and I have heard the Shrimp snap at him. Could the Shrimp have incapacitated him? He is still breathing but just lying on the sand bad. What else could be wrong with him and what can I do to try and save him? All parameters are normal.