To much aeration?

So I have a problem... I currently have a 4-5inch rainbow wolf fish in a 55 with 2 eheim classic 600, my problem is that when I turn on the air pump the wolf fish starts breathing hard (it's gills start opening wider as if its lacking oxygen), so i tested this and turned off the air pump the fish seems to prefer this, but I've tested with small feeders and they gasp for air at the top of the tank and then die from suffocation. So anyone know why this is? Seems weird to me because other fishes that I throw in there will suffocate, but the wolf fish prefers no air pump? Any ideas would be helpful.

Thank You

Other than the fact that the fish is breathing harder when pump turns on Does he show any other signs of distress when it is running. It could be he is trying to absorb the newly found oxygen in the tank. What are the other water parameters perhaps something else is wrong with water that that fish has adapted to. It would seem odd that new fish suffocate while that one seems fine. What about at water changes how does the wolf fish act?