How Often Do Goldfish Breed And Lay Eggs?

Does your love for goldfish have you considering breeding them yourself? Have you ever wondered if your goldfish will begin breeding on their own? Are you worried that you’ll end up with a bunch of baby goldfish that you can’t take care of?

So, how often do goldfish breed? Is this something you need to worry about?

If you’ve ever had questions about the breeding habits of goldfish, keep reading.

How Often Do Goldfish Breed?

In an outdoor pond, it’s typical for goldfish to spawn 1-3 times in a breeding season. In an indoor aquarium, goldfish may continue to breed throughout the year.

When Do Goldfish Begin Breeding?

Goldfish can begin breeding at just one to two years old. Considering goldfish can live for 20-30 years, this provides a lot of time for them to breed.

How Often Does Breeding Occur Outdoors?

Breeding behavior occurs when the water becomes warm and food is plentiful.

Breeding happens from late May through early June. Goldfish usually only spawn once in a season. But, breeding behavior will occur every day until the female lays her eggs.

If the water stays warm for long enough, goldfish living outside may spawn 2-3 times in a single season.

How Often Does Breeding Occur Indoors?

Goldfish raised indoors where temperatures stay consistently warmer may breed throughout the year.

But, you might have to encourage breeding behavior. They aren’t likely to start popping out eggs on their own. Even if they do, you don’t have to worry. The parents will eat their eggs if you don’t remove them from the tank.

How Do Goldfish Breed?

The female is the one that will initiate mating. She will send out pheromones that tell the male she’s ready. The female will begin to develop unfertilized eggs which lead to a bloated belly.

The male will then begin to chase the female around the tank, causing her to drop her eggs. She will lay her eggs and they will stick to any surface they’re able. The act of laying eggs is not always quick. It can take some goldfish over a week to deposit all their eggs, so it can be a very stressful time.

The male follows behind to fertilize the eggs with his milt — sperm and seminal fluid.

During this time, the male will also develop breeding spots on his gills that look very similar to ich. But don’t worry, this is normal and is nothing to worry about.

How Many Eggs Do Goldfish Lay?

A female goldfish can lay up to 10,000 eggs during a single spawn. Not all these eggs will be viable, though. The male will not be able to fertilize every single egg. Plus, the fry is very fragile when they hatch. It’s estimated that only 30% of goldfish fry actually survive to adulthood.

It will take between 4-7 days for the eggs to hatch.

What Can You Do To Get Your Goldfish To Breed?

If you’d like to breed goldfish, the first thing you should do is choose healthy fish. You might think this is a no-brainer, but it’s important. Select fish with a healthy body shape and with no history of health problems. Choosing healthy parents will provide you with equally healthy offspring. Goldfish without health problems will lead longer and happier lives.

Breed At About 3 Years Of Age

Although goldfish can begin breeding at one or two years old, you should wait until they’re at least three. This is especially important for female fish. Breeding takes a harder toll on their bodies.

A goldfish that is three years old should be completely grown. Breeding is safer and easier on the body when the goldfish is grown. It ensures that the reproductive system is fully developed to handle creating eggs.

Waiting a few years also gives you a chance to keep an eye on your goldfish. Any genetic mutations or diseases should present during this timeframe.

How To Tell Male From Female

If you plan to breed, you should know that you have both male and female fish. It’s hard to tell the two sexes apart, but not impossible.

A male’s vent will be slightly caved in, while a female’s will protrude. The males will have small tubercles on their heads, gills, and the front of their pectoral fins. A female’s body also tends to be rounder, especially in the abdomen.

How To Encourage Breeding

Outdoors goldfish will likely breed on their own without any intervention from you. If you keep your goldfish inside, you might need to encourage them to breed.

You’ll need to gradually raise the temperature of the water. You should start at about 50°F and slowly raise it to 74°F. Do not raise the temperature too quickly or your fish may go into shock. Instead, raise the temperature about 2-3 degrees every day.

This will simulate springtime for them and encourage them to spawn.

Move Your Goldfish To A Breeding Tank

Once you see your goldfish exhibiting mating behavior, move them to a breeding tank. The female will deposit her unfertilized eggs all over the tank. The male will follow along behind to fertilize them.

You should keep the bottom of the breeding tank bare or the eggs may become lost in the gravel. You can place a few plants or a spawning mop in the tank for the eggs to stick to.

Remove The Parents After The Eggs Are Laid

Once the female lays her eggs, you should remove her from the tank. You should remove the male after he fertilizes the eggs. If you leave the parents, they will eat the eggs.

From there, you’ll wait for the eggs to hatch. Then, you’ll need to care for the fry.


Goldfish that live outdoors will breed 1-3 times a year. Goldfish that live in indoor aquariums may breed throughout the year. Plus, goldfish can lay thousands of eggs at a time.

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