Want to know if your goldfish is a male or a female?
You’ve come to the right place!
Whether you’re naming a new fish or want to get into the hobby of breeding them, knowing how to tell the gender of your goldfish is a skill you’ll want to have under your belt.
WARNING:
None of these methods below will work if your fish isn’t old enough.
So, when does a fish reach maturity?
For most, it is around a year of age, sometimes as early as 9 months.
If you got your fish from a pet store it can be difficult to know when your fish’s birthday was (unless you can use a microscope to count the rings on their scales), so you might have to keep a lookout for the signs of maturity to arrive if your fish is still pretty small.
Ready to get started? Read On!
When it’s Best to Tell a Goldfish’s Gender: Breeding Season
Even experienced breeders can have trouble telling the gender differences between a boy or girl goldfish if the fish isn’t in breeding season.
But if you know what to look for (and you catch your fish at the right time), it can be a cinch.
Goldfish typically come into breeding season after a period of cold weather followed by warmer temperatures and more abundant food. This happens very commonly in the pond environment.
This “triggers” their reproductive stage and is the prime time to spot a male or a female using the clues below.
- You May Also Like: How to Breed Goldfish
How to Tell the Gender of Your Goldfish
1. Check for breeding stars on gills, body and fins
One of the easiest ways to know if your fish is a male or a female is pretty straightforward:
Look on the fish’s gill plates for the presence of tiny white dots, called “breeding tubercles” (sometimes also known as “breeding stars”).
These little dots look like little grains of salt and are rough to the touch, like sandpaper.
Breeding tubercles will also commonly show up on the front rays of the pectoral (front) fins of the fish as well, and even on the scales of the body!
Note:
These white dots sometimes are confused with the disease ich, or white spot disease.
But ich is different on the body in that it shows up randomly on the body and is usually larger, whereas breeding tubercles appear in neat rows on the scales.
If you see these, your fish is a male.
(99% of the time anyway – very VERY rarely, a female goldfish may have these for some unknown reason.)
What are they for?
Some speculate that they are used to “push” around female goldfish during breeding season. Others say they could be a weapon for the fish to use on other males.
But don’t miss this:
Just because your fish doesn’t have breeding tubercles doesn’t automatically mean it’s a female. Males don’t always show them, and sometimes they come and go depending on the environment and age.
2. Examine the vent shape of the fish
The vent is the part of the goldfish that releases their waste (as well as eggs or milt).
It is located underneath the anal fin(s) of the fish which are below the tail.
Females have a round “outie” that can be best seen when you look at the fish from the side. It is a small whitish protrusion that shows up when the female is close to spawning season.
Males have an oblong “innie” that is usually longer than the females, as well as more indented.
Judging by vent shape can be pretty tricky unless you are really familiar with telling goldfish gender.
3. Study the body confirmation
There is another way to tell if your fish is male or female, and that is by the shape of their body.
This is probably even trickier than the vent method, because of everyone’s different feeding habits. It’s probably a good idea not to rely completely on this one way when sexing fish and take the other factors into account too.
Also, if the fish is a Pearlscale, it probably won’t be easy to tell either.
It is best to use this tactic viewing the fish from above.
Here it goes:
Females usually look shorter and rounder in their abdomen area.
As they come closer to breeding season they can become very plump, swelling with eggs, like a dumpling. Their bodies are usually deeper as well when viewed from the side. This is called “gravid.”
Sometimes they may even look “lopsided,” with one side of the body bulging out more than the other.
Note: a really swollen belly on a goldfish can also be a sign of illness like a bacterial infection, so if the fish looks very swollen and not just pleasantly plump, make sure everything is okay. The swollen female fish might also be egg-bound, which happens when the fish produces a lot of eggs that continue to build up inside the abdomen and cause bulging.
Males on the other hand will often look thinner and longer in the abdomen.
Some males may also have a “seam” or a “ridge” along the underside of their belly.
4. Look at the shape and length of front fins

Image Credit: HamsterMan, Shutterstock
The front fins of a male goldfish are often longer and thinner than females, which usually have shorter front fins with thicker leading rays.
Of course, if the fish is a long-finned variety such as a Veiltail, this method may be pretty much impossible to use because their fins are so genetically enhanced.
This is probably one of the trickier ways of determining gender, but it can work very well if you have a group of mature goldfish that are all the same breed.
5. Watch the fish for signs of mating behavior
The most obvious way to tell a male from a female goldfish is to observe the spawning process in action.
Males will be the “chasers,” following closely underneath the belly or behind the females, nudging them and sometimes pushing them into objects or plants in the tank or pond.
Females will be on the run and sometimes might get tired or have torn fins from the rigorous process.
This is the only 100% reliable way of sexing your goldfish but your goldfish will have to be in the height of breeding season.
Wrapping it All Up
Now that you know how to tell the sex of your goldfish, what are you going to do?
Is your goldfish a male or a female?
Let me know what you think in the comments below (I always love hearing from you)!
you make these goldfish sound like the coolest animal on the planet
That’s because they very well might be 😉
I agree! Lol!!!
I have 2 double tailed goldfish. One’s a Calico and the other, I’m not sure, but it just looks regular orange. I think, based on this, that the orange one is female, but I’m not sure about the Calico. The Calico seemed to be chasing around the orange goldfish for a while, but it stopped after a little while. Maybe it’s male?
Could be.
I have two goldfish one fish is chasing the other fish that chasing fish is bigger than the other fish I think it is a boy. And the other fish is smaller than the other fish I think it is a girl.
my fish is a fan tail and its very hard to see his/her vent. therefore I can’t really tell what gender it is. do you have any more tips for discovering its gender. as for seeing finites a chaser, its companion died a few montes ago ;(
such a great website though.!
*months
Umm I know this might be a little idiotic buuuttt I got a fish from the fair and yes I know those always die but I decided to give it a shot my friend has had a fair fish for almost 4 years now anyways will this work on a small fair fish???
Probably not. They need to be around a year typically to be able to tell the gender; most fair fish are probably 6 months or less in age if I had to guess.
Those are the only ways I’m aware of! It might take longer if the fish is still small. Glad you like the site 🙂
I bought 2 orange goldfish and by the body looking big I think my goldfish are 2 females which I’m glad I dont need little fish my tank ain’t big enough for anymore fish!
Sorry for.your loss?
it’s good
Thank you ^_^
It’s good
Thanks Jamie! 🙂
Is this for regular or fancy goldfish?
Both.
just got them to eat lettuce Pure Goldfish!
thanks spike
Yay congrats 🙂
Excellent !
Thank you, Mike!
What kind of veggies do they eatand how do you give it to them ?
Check here for your food question 🙂
Thank you I was able to confirm if my goldfish was a female or male, she was a female like I thought, so now I can go get her a mate today
Glad it helped you Syd!
I have two comet goldfish and they are expressing mating behaviors! For example one fish Keeps constantly following the other fish everywhere it goes especially under the belly and behind it, think he may have tore her fin from pushing her around lol annoying just Ike my husband ????
They can be kinda rough!
I posted a pic of one of my fish after I caught it in a net(I put it back quickly) and someone told me\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\”he\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\” was a girl. I asked how they could tell and they said \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\” because of her angelwing tail\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\”. I was expecting something about the find. Can I send you a picture?
You can join our FB group and post your photo there to get some input!
I still can’t tell whether my 2 fish are female or not.:( I really want more fish but without buying them! Any tips?
It’s not always easy. The article contains all the tips I know.
Thanks that helps a lot!! Now I can act accordingly if im to breed these perdy fish i found in the cow troughf! found 9 pearly multicolored fish about 3 in long.apparently the farmers granddaughter put some in there 6Years ago! Named my favorite one”Sun puddle” witch can be boy or girl. Turns out its a boy!
Cute!
I have albino fish so I couldn’t really tell if they are female/male,but…I used the other hacks and figuired it out 🙂
Rating:Amazing
Im sorry to be a bother idk if its even a goldfish, but I can’t tell if it is a boy or girl. It has the white spots on its gills but I can’t see its vent easily. Any tips on checking its vent without stressing it out?
Probably a boy if you see the white spots.
Is it normal for a female goldfish to chase the male?(they’re in a 10 gallon tank)
Usually its the opposite.
me fish are 2 bois nd 1 grill
I have 5 goldfish. Thanks to you, I know I have two females and three males.
Thank you! It’s so amazing! I found out my three year old fish named chuppy was actually a girl lol. Also I got a new gold fish that I think is a male! I was wondering if the black tips on the tale and fins of my new fish mean anything…
Hey PureGoldfish! This is a very great info about the gender difference. But get this, I was wondering for a few months if a goldfish is over the age of 2,3,4, or beyond those ages, would they still breed even if they are too old? I found 3 rescued goldfish who needs for a home and a fish keeper told me, the two of the white comets are boys and they’re around 9 1/2 years old while the female common is at the age of 13 with fading red colors on the top of her body. Currently they are still living in a 120 gallon aquarium and they were fed Hikari and Omega One unlike their former owner. I am still thinking about this, so is it possible they would spawn at an old age too?
I’ve heard of them breeding beyond 15 yaers old.
I think this is very helpful but i still dont know what gender my goldfish is but i would guess a he also Speckles is his/ her name( i only have 1)
I have a goldfish that I thoroughly believe to be a male. His name is Nemious (Nemo for short) and he just got an upgrade for his bowl; meaning he just got transferred from a bowl to a tank today. His habits have gotten a lot better but speaking a bit more about your methods, he seems to have the indented vent like you said, as well as the white speckles, meaning he should be a male. He also seems to portray a thinner body shape as male goldfish should.
Also, I am getting a second goldfish for my birthday in two days, and I’ll make sure to bookmark this page on my laptop so that I can use these methods to find out the gender of the new one. I was thinking about a gender mutual name to give the goldfish, and though names such as Shannon (humorously) and Erin/Aaron. I decided on a completely wild name: Latice. And that would be pronounced luh-teese. I can’t wait to get my new goldfish!
Thank you for the methods you have enlightened me with! Now I can be aware of my fish’s gender.
Thanks for sharing! Glad the article helped you figure out your fish’s gender!
Can a female fantail goldfish rest on the bottom of the seafloor if she is pregnant or swim around less? I’ve notice a smaller fantail following her around and she’s a bit rounder than our other fantails in our pond.
Yes. For sure.
I am keeping a 2 goldfish in a glass bowl, is this good for them?
Check out this post 🙂
Hello thank you it is an important think
good work mam
I just got two fan tails one is orange and the other is black can’t tell if male or female you can text me at *phone number removed to protect privacy* I would like to know
You may want to post a photo in our group of your fish, Brian 🙂
I do believe my goldfish is a male but I’m not sure if he’s mating or not. He has white balls that go in and out of his big bubble eyes . He is the only one in the tankit is 15 gallons he’s black and gold and he remembers when you take something out of his tank that he’s used to this is new and I’ve had him for a year. Would love some info email me okay.
Started out with 5 Feeder goldfish. They are now about 6/7 inches long. I do remember seeing a few of them chasing one in particular. I now know which is female. Well,early October I noticed a small fish swimming in the pond. It took a couple tries but I caught it and put it in our 5 gallon tank in the house. It’s orange/white and about 2 inches long. The same coloring of the one I believe is the female. In the past few weeks I found 4 more little ones. Bought a 10 gallon tank and all 5 are now in there. But the 4 are brown in color. The 5 big ones in our pond,one is orange/white and the other 4 are the traditional orange “gold” color. Since then I see at least 2 more little ones,but they only seem to come out at night,just like the other 5 little ones. I tried but can’t seem to catch them. The weather is getting colder,I live in chicago,and someone said the little ones might not make it through the winter in the pond. I do have a De icer in the pond and have not seen the little ones for days now. The big fish are semi in hibernating stage now. Just wanted to share my story and if you have any advice it would be welcomed.
You probably need to keep trying to catch them. Under 3″ they may not make it.
I have 2 comets.
one of them chase the other one.
But the chasing one is fat,round,shorter.
And the chased one is longer,thiner
I’m confused about their gender please help me.
Might want to see this post.
Meredith I’ve read Comets can sometimes be sexed by the V shape of their tail. Males have a more acute deep V shape than females who tend to have a more shallow V. Have you ever heard this? I’ve correlated my tail based gender assumptions with actual spawning behavior and there does seem to be some truth to it. What are your thoughts?
I too have heard that but don’t know how reliable it is personally, but if it works for you there may be something to it!
I don’t know.
Can goldfish gender can be differentiated by their tail? I have a pair, one with logner tail than the other.
I have heard of this but can’t confirm if it is a reliable method or not.
Hey Meredith!
My name is John and i just adore me little fishies. They live together in a massive tank next to my bed. When i get up each morning i see all of em waving their little fishy fins and blowing their bubbles at me. Ive just gone and bought myself a pair of little blue ones and I’m wondering what gender they are since its always been my dream to name a few fishies ‘Smoked’ and ‘Salmon’. I just really need to know their gender because those names are boy names and i dont want the others to tease them if they’re girls. Also i dont want to leave them unnamed because they might feel left out. I named the others within a few minutes of buying them, i dont want these little guys to feel like they’re less special to me in my heart. I believe that all fish deserve fairness and equality and fish shouldn’t be put down by other fish just because their owners are too indecisive to name them quick enough. Please give me some tips on gendering fish and if you’ve got some useful unisex names that might be suitable for a pair of small, blue fishy friends, please let me know!
Thank you so much,
John
Dear John,
Unfortunately, despite your beliefs, fish don’t actually have feelings and they really can’t put each other down. Haven’t you ever heard of a fish’s ‘three second memory?’ I really think that you shouldn’t be wasting other peoples time and if you want matching unisex names for your fish, how about ‘lunch’ and ‘dinner’?
Thank you now I know Gilbert is a boy.
Sam,
Not only do goldfish have feelings, but this ability might have evolved hundreds of millions of years ago. Emotional states in animals are still a matter of debate for biologists. Now, for the first time, Portuguese researchers have demonstrated that fish have emotional states triggered by their environment. Plus fish love there owners and recognize then.
I have 2 pearlscales one yellow other orange it seems all of a sudden the orange one looks like its gonna burst what is this plesse
Could be dropsy
Hey Meredith, I have a slight question about one of my Fantails for you. About maybe a month and a half ago, my fantail got a small white lump on one of his back fins, and it got a bit crooked. I figured it\’d go away with time, that it might be a breeding star or something. Now its a fair while later, that fin has a few more white spots, though not as raised as the first. My fish doesn\’t seem to have any other symptoms, and it hasn\’t spread anywhere other than that fin. He acts perfectly normal and sticks close to my other fantail. What do you think this could be, because it\’s not spreading like ich and I don\’t just want to instinctively dose the tank with MinnFinn unless I know its a disease.
How long have you had him? Could be a broken ray
I\’ve had him for nearly a year now. How would I go about fixing a broken ray?
The fish live fine with them. No way to fix :/
Thanks for the info now I know who the father of the mysterious baby goldfish is as I thought they were all the same sex