How do you tell the sex of a fish

This article has also been viewed 1,, times. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. If you want to learn how to tell your goldfish's sex by their behavior, keep reading the article! Understand that gender differences will only appear once the goldfish reaches maturity. Together, they cited information from 11 references. In addition, some breeds of goldfish do not comply with general rules - for example, some breeds such as ranchu or ryukin naturally have very round, thick body shapes, which makes gender identification through body shape almost impossible. If you have a goldfish, examine your fish for small clusters of bumps on the forehead, gills, and fins, as these are signs it is male.

Article Edit. The male Moonlight Gourami has orange to red coloration of the pelvic fins. The only way you can really tell is by seeing if it starts laying eggs, in which case it would be a female.