How Can You Tell if Your Goldfish Is Pregnant?

The Basics

Goldfish are not livebearers, they lay eggs. This means they don’t produce live babies. Goldfish don’t get pregnant. However you do need to have a mix of male and female goldfish in order to produce fry.


The goldfish breeding process can be complicated and owners who understand the process will better understand their goldfish.

preparing for fry
To increase survival rates set up a separate breeding tank with filtration

Determining the sex of the goldfish can be difficult, but if you know these characteristics it will help with telling them apart.

Male goldfish characteristics

  • Males are generally smaller
  • They have firmer stomachs than females
  • Pectoral fins of male goldfish are longer

Female goldfish

  • Pectoral fins of a female are shorter and rounder

Signs goldfish are ready to breed

When females are ready for breeding, their stomachs will become rounder due to their stomach filling up with eggs.

Some people believe this is how you can tell if your goldfish is ‘pregnant’.


Males develop white breeding tubercles on their gills during this same period.


The breeding process can be fascinating to watch and it may appear that the female goldfish could become pregnant in the process. However the female actually lays eggs in clusters and the male swims over the eggs releasing sperm to provide fertilization.


Carefully watch the goldfish for changes in behavior. If egg deposits are noticed, they should be removed from the tank and isolated from the other fish.


The eggs will normally stick together and be easy to detect. Note: If the eggs are left in the tank, other fish are likely to eat them.

Breeding tank and caring for goldfish fry

When eggs are dropped by the female, they’ll fall through the slots in Slotted V-Trap, carried through the maternity connector and transfer tube and brought up into the nursery tank.


This tank can then be lifted gently off the nursery platform and placed into a separate aquarium.


Keep in mind the eggs need to be placed in a separate tank with a filtration system. A sponge or under gravel filtration system works best. This way when the eggs hatch, the fry can’t be sucked up into the filter.

goldfish breeding nursery
egg deposits should be removed from the tank and isolated

Check price of an ‘aqua nursery’.

After a short period of isolation, little fish ‘fry’ will begin swimming in the new tank. If this happens, the breeding process was successful. It’s perfectly normal for only some of the fry to survive.


Feed the new fish powdered fry food or brine shrimp for best survival rates.


Keep the tank clean and enjoy the view.

Preparation for the fry is important for their survival. They need a separate tank, filtration and correct food. Once this is in place you can enjoy this fascinating lifecycle process of breeding goldfish.

We found this interesting video and it gives some great visuals on the process of goldfish breeding and shows the different stages fry hatching and growth.

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