I know is almost inpossibal for us to tell the sex of our oscar with out removing them from the tank but i wanted to know at age can oscars tell each others sex??? Are they always aware of each other sex like people or do they have to wait till puberty to work it out?
Just asking cause i have recently added a juvenile O in with my one yr old male. There is a little bit of bullying from the older guy but nothing serious just a bit of pushing the younger one round with his mouth open, no marks have been left on the younger one while this has been happening, it dosn't seem serous. The younger one just gets out of his way and they almost always hang at oppisite ends of the tank.
Cheers

when maturity hits, if you have 2 males the battle for dominace will start. when mine started the battle for dominance it came on quickly and fairly violently.

yeh i had 2 males to start with but thats exactly what happened....i had to get rid of one, i added a new one in hope its a female....so i guess i just wait for puberty to kick in

unfortunetly yes only time will tell