I've had this green mandarin for 3 weeks now and he's been doing great pecking at rocks eating pods until tonight i realized he isn't swimming right more like rolling through the water and i believe he is missing fins. Some of the fins looked to be laid down but im thinking some are gone. What could be causing this. Only tank mates are 2 snowflake clowns which haven't bothered him at all, a yasha goby paired with pistol shrimp, lawnmower blenny, emerald crab and cleaner shrimp which is now folling him around bothering him. Anyone have this issue before?