Goldfish breeding season? Male and female differences

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Recently, two bronze fantail goldfish have joined our home!

As it happens, these gold fish are one male and one female and are ready for breeding season.


When is Goldfish Breeding Season?

According to books and online resources, goldfish are not hard to breed.

From spring ~ autumn, when water temperature is around 20C, they may start breeding.

Some goldfish kept indoors with water heater to keep warm water temperature may breed regardless of what outside season it is.

Outdoor goldfish are more likely to start breeding in spring to early summer, when water temperature gradually rise.

How Old do Goldfish Have to be to Breed?

Apparently, goldfish older than 1 year are capable of breeding.

So babies that are born in spring, grew over summer ~ autumn and manage to survive through winter, should be able to breed in next spring.

But gold fish breeders use 2-5 years old goldfish for breeding, so that appears to be their ideal age for breeding.

Telling Male Goldfish From Female Goldfish

Normally, identifying the sex of a gold fish is difficult for even pro-goldfish keepers. It is almost impossible task for novice like me.

So how do I know that my goldfish are one male and one female?

It is because now is the start of breeding season!

Breeding Male Goldfish with White Pimples

In the right season, breeding males are easiest to identify.

Breeding males start to develop “white pimples” near their gills and sometimes also on front fin.


My male goldfish


White pimples around gills and front fin (pointed out by red arrows).

It was more visible on this (right) side of his body.

These pimples increase in number as males get “more” ready for breeding.

Do keep in mind that if you see white pimples through the body, this may be due to some disease.

Breeding Female Goldfish

Breeding females on the other hand, does not have any of “white pimples”. They start to become a bit ore round, as they accumulate eggs in their tummy.


My female goldfish; her body does look round especially the lower belly.


Absolutely no white pimple on her gill.

Look for Signs of Male Goldfish Chasing Female Goldfish

When male and female goldfish are together in a fish tank in right breeding season, then male gold fish will follow around female goldfish.

So if you see a gold fish that has white pimples only around gills (and possibly front fins), that is chasing another goldfish without pimple and with a round-belly, then it is most likely male goldfish chasing female goldfish.

This is the easiest way to identify male and female goldfish, I think.

So hopefully, if I take a good care of these two goldfish and give them plenty of food, they will lay some goldfish eggs, and may be able to meet little baby goldfish.

Cannot wait!


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