hi there i am new to keeping saltwater fish i have had my tank up and running for 2 months now all water levels are good have shrimps crabs clown fish and a gold rimmed tang lots of soft corals and a sabae anenome african i think it has moved around the tank a bit but did settle in one part of the tank for just over a week my clown fish have taken to it very well but tonight when i came in i noticed it was spinning and turning round the tank only one part of the tank its mouth is open very wide and is very puffed out but the base is short and stumpy i have not seen it do this before and i am concerend about it is this normal ? can anyone help please