Oscars

Question
I have 2 oscars, and we had them since June 2010. They are currently in a 55 gallon tank. 2 days ago they locked onto one anothers mouths and pulled back and forth with each other and kept at it for about 3 hours and they started doing it the next day for about 2 hours. Now last night and all day today, my black oscar is fine, swiming normal and everything, however my white oscar is laying at the bottom of the tank and only moves when the black oscar comes nears it and goes back down. The white oscar doesn't appear to be injured in anyway from my viewing. What can be the cause of this? Where they mating?

Answer
Hi Mindy,

They were, indeed, mating.  That is a courting behavior they exhibit before spawn.  It can also be a territorial behavior between males.  

The one who's backed down...keep an eye on it for injury.  Especially around the lips.  Should you see swelling, add a half cup of salt (marine salt) to the tank and watch them for signs of infection, but if you don't see any signs of injury, of course...no salt.

Just watch them.  Most likely, they are not two males, but are instead male/female.  They may begin moving stones and gravel soon, uprooting plants and redecorating to spawn.  Provide them with a smooth slate piece and watch them go to town. :)

Happy fish-keeping.

Renee