How To Look For A Pregnant Goldfish?


A pregnant goldfish swells with eggs but doesn’t carry them in her womb. She’s not human; she’s just an oviparous animal. This means goldfish release the eggs in the tank or water, which connect with the sperm of the male goldfish.

Goldfish start breeding as soon as they become four inches long. Male and female goldfish begin to develop physical and behavioral changes before they release their sperm or eggs. And this particular stage is known as milt.

Not many fish owners or breeders know that goldfish reproduce quickly. And this is the reason why they fail to notice the eggs before the goldfish eat them. Yes, that’s right. More often than not, goldfish tend to eat their eggs after releasing them.

So how to tell the difference between a fish that’s expecting and one that’s not? If you keep reading, you’ll soon find out!


Pregnant Goldfish: What does She Look Like?


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Female goldfish tend to look pregnant only when they’re ready to deliver the eggs. And mature females start developing eggs during early spring and late winter. These eggs begin to swell, which makes the belly look fat.

You will be surprised to know that even male goldfish go through physical changes during the breeding phase. The pectoral (side) fins and gill covers develop white bumps.

Behavioral changes in male goldfish include chasing the females and bumping their bellies and sides. This is only to encourage them to discharge those eggs to begin the fertilization process.

How to Tell If a Goldfish Is Pregnant?

Spring Fever: When do Goldfish Breed?

When the temperature of the water rises, that’s when goldfish breed. To be precise, it’s when the temperature hits 68 degrees Fahrenheit that females release hundreds or even thousands of unfertilized eggs.

Once this happens, the male goldfish discharge their sperm within the same region to fertilize those eggs. The process is known as spawning, and it usually occurs early morning. The breeding stage lasts for at least 3 to 4 hours.

These eggs then attach themselves to the tank or water’s vegetation. Fertilized eggs tend to be golden brown but transparent. On the other hand, unfertilized ones are white.

Hatching Time: What Happens after Fertilization?


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Once the pregnant goldfish releases her eggs, and they connect to the sperm, the hatching process takes place. But it only happens after 5 to 7 days of fertilization. When the temperature of water reaches 84 degrees Fahrenheit, the fertilized eggs take 54 hours to hatch. And when the temperature hits 75 degrees Fahrenheit, the eggs hatch in 7 days.

Very few people know this, but goldfish fry have yolk sacs. These perform the job of supplying food for as long as three days. Once the sacs become empty, the fish consume live food like daphnia and brine shrimp.

Goldfish don’t tend to look after the young fry. In fact, goldfish even end up eating them most of the time.

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Breeding Goldfish

pregnant goldfish

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For breeding, you need a female fish that is ready to deliver the eggs and an adult male fish. If you have these two, you can breed goldfish at home. You also have to get a new, clean tank for the many goldfish fry.

Begin by placing a clean, new mop head or spawning mat with the breeding goldfish. Check the tank each morning to spot the eggs. Once you notice them, transfer them to their new tank. After about 12 hours, you will see unfertilized, white eggs, which you need to remove from the tank.

You can feed your goldfish fry at least three times daily but only when the yolk sacs on them shrink. Please don’t overfeed the goldfish fry and don’t pollute the tank water as well. You should know that goldfish fry consume live food, specialized liquid food, and powdered flakes.

Goldfish Breeding Facts

  • Goldfish lay eggs, just like birds. That makes them oviparous and not livebearers. They don’t give birth to live babies. And this means that goldfish don’t become pregnant.
  • The breeding process of goldfish is quite complicated. And not many owners know much about it. So if you want to understand your fish better, it’s advisable to know everything you can about the breeding stage.
  • When you want to breed goldfish, you need to get a mix of both female and male fish.
  • It’s difficult to determine the gender of goldfish. The best way to go about it is to look for longer pectoral fins and firmer stomachs. These are found in male species. While the female goldfish have pectoral fins that are rounder and shorter than their male counterparts.

Also, male fish are comparatively smaller than females. So this constitutes as a clear distinction between the two.

That’s About It!

Animals either lay eggs or give birth, right? And goldfish tend to reproduce by laying unfertilized eggs which connect to the sperm for fertilization. If you know a lot about fish, then you might be aware of the fact that only guppy fish are livebearers.

In an aquarium or outdoor pond, goldfish readily breed in an optimal setting. You just need to know when the female goldfish is preparing herself to spawn. Failing to do so might end up costing the lives of hundreds and thousands of baby fish.

So now do you know what a pregnant goldfish looks like? And did you through the Breeding Goldfish section thoroughly? It discusses how to breed goldfish most efficiently.

I hope the article helped in answering all your questions. Is there anything that you think I have failed to discuss? Please let me know.

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