Roderick

it started last night, my oscar swimming around with his mouth open. he has been doing it all day. he is still eating and swimming, the other fish are fine in the tank. there are no battles between fish and my tank is not over stocked or to small. Does anyone know what he is doing??

Jim

I would test the water for all the usual things: Ammonia, Nitrites, etc. If everything checks out normal, then it might just be he's being an Oscar.... and Oscars are known for being pretty weird!

Roderick

thanks for the info, aammonia levels were a little high, so fixed that problem and I will see if it has helped oscar. thanks for replying.

Gunnie

When my oscars' mouths are open, it's because they are fighting. Is your oscar being aggressive toward any other fish in the tank?

L a r r y

I've got an oscar that is doing the same thing. I got a pleco, that was wayyy too small, and found that he had it in it's mouth. Eventually he spit it back out, but now swims with his mouth open ALL THE TIME. Could it have possibly gotten LOCK JAW or something?

darkwolf29a

If it's not water parameters...it's being weird. Ody(sseus), my Oscar, should have been named Oddy. He swims weird all the time, until I look at him. It like he's just trying to get my attention. LOL

Jim

It does sound like he might be posturing... I just thought of something... sometimes, when the light was just right, my oscar would see himself in the tank glass... and go after his reflection just like a betta! it was fun to watch; his colors got brighter, he would puff up his gills, and open his mouth really wide. Sometimes we would use a mirror and he did the same thing. And sometimes, if I set something right outside the tank, he would glare at it and again go all agressive. My point is, oscars can see very well outside of their tank, could there be something there in your room that's setting him off?

b0n3ZA

Possibly the FHM posters on the wall.