Lionfish is not right?

[GigaFish]

I came into my office on monday and my lionfish looked sick. His color is very faded, almost like he has dry skin. He is not eating. He is sometimes swimming upside down. The scariest part though is that the bottom pectoral fins are shaking like he is shivering. Does anyone know whats going on here?

PH = 7.9
Amm,Nitrite,Nitrate = All 0