rapid breathing

Guys I need help very urgently , I added be to my arowana tank and he is breathing way heavy his ribs are poke out not moving much not eating at all I am freaked out don't know what to do this my first ray and experience going way bad my water parameters are up to mark he is holding his body...

I have kept a Gulper catfish for a couple months now in my 75 gallon tank. He’s alone in the tank, and the tank was cycled previously (all the parameters are well within acceptable range). When I got him, he was in very bad shape. He was malnourished, pale, breathing rapidly and developed ich...

Hey guys. I've just moved my 2 years old Asian Aro to his new tank 2 days ago. He's been having problem with heavy breathing since. His new tank has these dimensions 72in x 24in x 16in. The tank is only 16in Height so it is not deep. I don't think the water level is high to cause heavy...