I have a 6 year old male Angelfish that has been unwell for 3 days now. It's not eating, has its tail on the gravel and nose pointing upwards. It cant swim normally, only in the same nose up tail down position. It also seems to be gasping for air.
I have a 450 litre tank, everyone else seems happy and healthy and the water is fine. This is an established tank, that hasn't had anything added to it recently and I have had the angel in this tank since he was a bubba. Any ideas would be appreciated. Thanks in advance.