How can i tell if my oscar fish is male or female?

Question

well i am ont sure if my oscar fish is male or female

Answer 1

Barbara NC is right, Oscars are monomorphic and there are no physical differences between males and females.  The only wat to tell is to vent them, (as Barbara stated above) or to wait till they spawn and see what the sexual organs look like when they protrude.

MFK

Answer 2

I am going to quote since the author summarized it best:

The only sure way to s*x an Oscar is to look underneath the fish. To the rear of the fish's a**s, is the s*x organ. In the females, it is a small hole. In the male, it is a phallic appearing outcropping. However, these are not readily noticeable without magnification, and holding a fish upside down under a magnifying glass is difficult at best.