Oscar Cichlids - Astronotus ocellatus • Oscar Acting Strange

[NCOLBY]

We've had our oscar for about a year now. A few days ago, he has started acting very strange. He seems to be constantly fighting with his reflection in one side of the tank. He holds his mouth open, he seems to be breathing hard (his gills are really moving), and staring at the side of the tank. Every now and then, he attacks the side of the tank spraying water everywhere, and I'm kinda afraid he's going to hurt himself. As far as I can tell, there's nothing stuck in his mouth. I don't notice any sores or injuries.

I do weekly water changes. The ammonia, nitrate, and pH levels are fine. The temperature hasn't changed. The other fish in the tank are acting completely normal, no signs of problems. Any idea what could have made my Oscar go nuts?

[Rob1984]

We've had our oscar for about a year now. A few days ago, he has started acting very strange. He seems to be constantly fighting with his reflection in one side of the tank. He holds his mouth open, he seems to be breathing hard (his gills are really moving), and staring at the side of the tank. Every now and then, he attacks the side of the tank spraying water everywhere, and I'm kinda afraid he's going to hurt himself. As far as I can tell, there's nothing stuck in his mouth. I don't notice any sores or injuries.

I do weekly water changes. The ammonia, nitrate, and pH levels are fine. The temperature hasn't changed. The other fish in the tank are acting completely normal, no signs of problems. Any idea what could have made my Oscar go nuts?

prolly see's his reflection and thinks it another oscar in "his" territory...

[AulonoKarl]

Oscars are insane. I used to have two and they would do this from time to time, pacing up and down at the side of the tank, watching their reflection and getting angry. I wouldn't worry. Oscars are clumsy giants with very hard heads. Mine ran into stuff at full speed on a regular basis and they didn't really seem to care and would always heal fast.
Mine would go through phases when they were just totally focused on territory. After a few days, they would just snap out of it. They are very strange creatures.

[mok3t]

My big guy (12.5") is constantly sparring with his reflection and has done so for about 2 years now. Occasionally he will ran some wood and wound himself a bit but a water change later hes usually back to normal. he did once try to move a slate slice with his face, ended up with a VERY deep gash and i'm sure i saw raw flesh. not that you'd know it now, water changes and melafix and a month later he was again, back to normal.

As Karl said, they are as mental as they are resilient.

Let him do his shadow boxing and enjoy watching a VERY powerful fish do his thing in your home. Its wonderful.

[SYcichlid]

It's normal behavior for oscars. Nothing to really be concerned about. Any pics or video of him would be a treat.