Odd behavior in oscars

[Chrisv32]

The other day my two oscars started acting strange. They stay at the bottom at feeding time when they would usually jump to the surface. Also, my biggest keeps jumping up out of the water when the least little bit of movement in the water startles him, and now he has large gashes on his head. I am very confused because they have never acted this way before. Please help if you can. Thank you.

 

[Soaup]

My oscars have never jumped and cut themselves, but any change in environment or water changes etc they almost slip into a depression where they just kinda lay on the bottom near one another and it usually lasts a few days. if there is anything to do to prevent your fish from cutting his head i suggest doing so. He could get sick if he stays stressed out for too long. Also maybe the tank isnt getting oxygenated enough.

 

[Chrisv32]

I have got adequate airation, and all of the levels are right, so I am really confused about how or why they are doing this.