How to Tell if Your Goldfish is Pregnant: 5 Vet-Approved Signs
Does your fish look round? Could it be that your goldfish has goldfish babies on the way? Animals reproduce in two ways: either they give birth to live young, or they lay fertilized eggs. Goldfish, unlike other species of fish such as the guppy, are not live-bearers, meaning that their babies do not start swimming around as soon as they are born. This means that they have to “lay” eggs instead.
The eggs will remain outside of the goldfish’s body until they hatch and the baby fish become free-swimmers. Read on below for some signs that your goldfish may be pregnant.
The 5 Ways to Tell if Your Goldfish May Be Pregnant
1. Chubby stomach
Round, chubby bellies on goldfish are sometimes spotted either at the fish store or in your own tank. Female goldfish may get a plump, gravid look. Not swollen—just kinda chunky. If the fish is swollen, bulging drastically, or has pineconing scales, you may actually have a sick goldfish on your hands instead of a pregnant goldfish. Problems like abdominal infections or organ failure can make a fish “blow up” far larger than normal.
Viewing the fish from above can be very helpful to check for pineconing scales—scales that stick out from the sides of the fish (see our article on dropsy). A fish might start to look a bit more swollen behind the gills and in the abdomen, if it is just starting to come down with dropsy or another illness.
Of course, a goldfish that just looks a bit fat could also very well be overfed. (Note—many goldfish are overfed!) An overfed fish ends up storing too much fat in their body, which isn’t good for its overall health. If your fish is overfed, you may want to check out our article on feeding.
Finally, your fish may still look completely normal and still be carrying a load of eggs.
2. Eggs coming out when picked up
If you reach your hand in the water to pick up your fish and a bunch of eggs come streaming out as she wriggles around in your hand… That’s a sure sign your goldfish is “pregnant!” This also means there are a LOT of eggs in your goldfish, and she is in prime spawning shape. A male fish might be just the thing to help her lighten her load.
It isn’t recommended for anyone other than seasoned breeders to try to “squeeze” the eggs out of their fish. This can cause potential damage to the fish, as well as considerable stress.
3. Being chased by other goldfish
Chasing only happens once female goldfish, who are ready to release their eggs, start releasing special pheromones into the water. This signals to the male goldfish that she is in breeding condition.
Here’s how it works—chasing is often mistaken for bullying, and is most common in the spring and summer months. Males will pursue the female from behind, trying to nudge her underneath her stomach. That releases the eggs so he can fertilize them with his milk.
4. Lopsided belly when viewed from above
Looking at the fish from above, a rounder, more lopsided belly can be seen on many female goldfish. This is oftentimes from the eggs filling one side of her body more than the other.
5. Male goldfish with breeding tubercles
This isn’t by any means a guarantee your fish is “pregnant.” But during spawning season, males will often show breeding tubercles on their gill covers and pectoral fins. These look like tiny white dots. It just means there is a possibility your fish have gone into the spawning season.
- The best way to tell if your goldfish is pregnant is by taking a close look at her body. When a female goldfish is getting ready to lay her eggs, she has dozens, if not hundreds of eggs inside of her. Therefore, she will get chunky, or in other words, she will look fat. She won’t necessarily look super overweight, but you will notice some chunkiness going on.
- If a female goldfish is full of eggs and getting ready to lay them, if you go to touch her or even pick her up, you may notice that some eggs may actually fall out of her. If there are lots of eggs inside of her, the body may barely be able to contain them, at which point they may come out.
- If your female goldfish is constantly being chased or harassed by your male goldfish, there’s a reason for it, and it’s because they can tell that they are about to get to fertilize some eggs and make some babies of their own.
- Something else which may indicate a goldfish full of eggs, or a pregnant goldfish, is if you look at her from a bird’s eye view her stomach is larger on one side than the other. This often occurs as a result of the majority of eggs resting on a certain side.
- If you see that your male goldfish have tiny white dots on their face, called breeding tubercles, it is a sign that they are ready to spawn. Now, it’s not a 100% sure indication that the females are pregnant, but it is a good sign.
Common Myths About Goldfish Pregnancy
Goldfish can get pregnant
Goldfish can’t carry live babies inside their bodies, and therefore cannot classify as “pregnant” at any point in their lives. More on this later.
If you are interested in breeding goldfish, but you’re unsure of exactly where to start, check out our book on Amazon, The Truth About Goldfish, which breaks down everything from breeding and raising fish to increasing your tank size to accommodate a bigger family.
Fish that sit at the bottom are pregnant
Fish that sit at the bottom most of the time are actually doing so because they are not feeling well. Or suffering from poor water quality.
Female goldfish will show “nesting behavior”
Goldfish do not nest. When they do lay eggs, they throw them EVERYWHERE—there is absolutely no consideration as to where the eggs will go. In fact, they will even eat their eggs the first chance they get. That said, you can make a “nest” for your goldfish if you suspect they are going to throw eggs soon. That way you can take them out of the water before they get eaten up.
Here’s a great tutorial:
Sluggish behavior indicates a pregnant goldfish
No. Sluggish behavior—not just a bit less of a “waddle” as they swim, but a truly sluggish attitude—is a sign of a health problem in most cases.
A pregnant goldfish refuses food
If your fish is refusing food, it’s because it’s sick. A healthy goldfish, even one carrying eggs, will always have an appetite.
Can a Goldfish Really be Pregnant?
Technically, to be pregnant, an animal must carry actual live babies in its womb. Unfertilized eggs do not count as babies because they are not alive! Only after they are fertilized can they begin to grow and turn into little goldfish. So, can female goldfish carry live young inside them, making them “pregnant?”
No. Goldfish cannot actually be pregnant because they cannot carry live babies inside of their bodies. They release unfertilized eggs into the water where the male fertilizes them and they wait to hatch. They are only alive once they are outside of the goldfish’s body and fertilized by the male, meaning that female goldfish never is pregnant to begin with.
She only is carrying potential baby goldfish until then.
Then What About that Belly?
So, what if your goldfish has a big round belly? Does that mean she is pregnant? No—but she may either be full of unfertilized eggs waiting to come out… or overweight! During breeding season, female goldfish will often grow larger around the middle as, in response to the warmer weather and romance floating through the waters, they swell with eggs.
Sometimes egg impaction can occur when the female goldfish do not have any males around to help them breed, and this may result in a highly abnormal swelling of the abdomen. Other illnesses can also cause bloating, so if your goldfish does not seem well it may be a good idea to investigate possible illnesses.
If your goldfish is overweight, you are probably feeding too much! Cut down on the frequency and size of portions (and feed a good quality food) and you should see improvement in your goldfish’s waistline.
How Long are Goldfish Pregnant For?
This question is misleading because, of course, goldfish are never pregnant. However, they carry eggs for a certain period of time before laying them. Female goldfish will develop a load of eggs every few months, and this can be anywhere from a couple of dozen to hundreds of eggs.
It will take roughly 3 weeks for the eggs growing inside of a goldfish to be ready to be laid. However, female goldfish will only develop eggs given the right conditions.
What Do You Call a Pregnant Goldfish?
There are a few different words that may be used to describe a pregnant goldfish. The most common word used to describe a pregnant goldfish is a “cowl”. Moreover, although respectable dictionaries usually avoid it, some people use the word “twat” as slang for a pregnant goldfish.
How Do You Take Care of a Pregnant Goldfish?
There is honestly not too much work that goes into taking care of a goldfish that is ready to lay her eggs. That said, there are a few things that you can do to help the female feel more at home and maybe even to speed the process along.
One thing that you can do is to create a spawning mop, or alternatively buy a spawning mop. Yes, as the name implies, this looks like a mop, and the point of these things is to allow a goldfish to lay her eggs inside of the spawning mop.
Spawning mops are designed to be soft surfaces for the eggs to lay on.
Increase Water Oxygenation
A pregnant goldfish may become more tired due to her increased weight, and she may also need to consume slightly more oxygen. Therefore, try to ensure that there is minimal water movement in the tank and try to very slightly increase water oxygenation too.
Goldfish can live in waters between 50–79 degrees Fahrenheit (10–26 degrees Celsius), and generally, goldfish live in the lower end of that spectrum. To get a female goldfish ready for her journey, you can slowly increase the water temperature to 68ºF (20ºC), increasing it by only small amounts day by day.
A pregnant female goldfish is going to require lots of energy, which is because she’s being chased by males, she is full of extra weight (eggs), and will need the energy to lay the eggs. In other words, feed your goldfish right and make sure that you are meeting her nutritional needs, if not exceeding them (more info on feeding here).
Goldfish Breeding Tips
Let’s go over some basic facts and tips that you can follow which should help you be more successful when breeding goldfish.
- A good idea is to remove the male from the tank about 3 days before you expect spawning to happen. This will greatly increase the want and need for the males to spawn or fertilize the eggs.
- A good idea is to always have a ratio of 2 males to 1 female. This will also help increase the chances of spawning and fertilization occurring.
- Feed the female additional food. Feed her 1 extra time per day, and slightly increase the amount of food per feeding. Also, give her many protein-heavy foods such as daphnia, brine shrimp, and other such things.
- Keep in mind that feeding your goldfish more food will lead to them creating more waste. It’s always good if the water is clean when goldfish are breeding, and therefore you will want to do a daily water change of 20%.
- As mentioned above, the cleaner the water the better, so make sure your filter is very clean and running at total capacity.
- Something else to keep in mind is that the optimal tank temperature for goldfish breeding is about 20 degrees Celsius. Therefore, if necessary, use an aquarium heater to get the tank water to the appropriate temperature.
- Something you will want to do once the eggs have been fertilized, preferably before the goldfish fry hatch, is to remove all adult fish from the tank. Yes, people, adult goldfish will eat eggs, even their own.
- Keep in mind that goldfish reach sexual maturity at 1 year of age, and at that point will be ready to start producing children of their own.
- A good idea to keep the eggs safe and to maximize hatching is to use a spawning mop, something which we discussed in the above section.
There you have it guys and gals, everything you need to know about goldfish pregnancy and breeding goldfish.
Honestly, chances are huge that if you have males and females in your aquarium, they will probably end up breeding, so be ready!
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