My silver arowana is typically so ravenous that I need to feed him quickly just to dodge him when he goes after the food! But over the past three days, I have gotten him to eat almost nothing. He turns down shrimp (usually his favorite food!) he only ate like two pellets, and ate only one, tiny cricket, despite eyeballing the others. My water tests came back fine, nitrates are low, ammonia and nitrite are nonexistant. He looks a little beaten up, but that is normal for him, he typiclly has managed to cut himself up trying to jump, and it doesn't normally impact his appetite. He is acting slightly more lethargic than usual, but is still swimming around the tank, and apparently jumped during the night (he knocked a heater off its bracket,) so he still has his strength. Any ideas what this may be? He's my baby and I'm worried sick 
thanks guys.
Edit: some things to rule out:
He has not been moved recently, he has lived there for over a year.
He has no tankmates to make him ill or injure him.
He is a little over 2 years old, and approximately 2 feet, 3 inches long. I've kept him since he was about 2 inches.
thanks guys.
Edit: some things to rule out:
He has not been moved recently, he has lived there for over a year.
He has no tankmates to make him ill or injure him.
He is a little over 2 years old, and approximately 2 feet, 3 inches long. I've kept him since he was about 2 inches.
I can sleep a little more soundly.
