Is your goldfish male or female ?

Goldfish are one of the most loved and preferred fish among the aquarists. The exotic color and flamboyancy they endow to the tank are unbeatable. If you can maintain a regular cleaning and proper care, goldfish can thrive well for a longer period, give an eye-catching look to the tank and become the center of attraction of the room in no time.

Generally, we buy fish when it is in its infancy. While they are young, it is not possible to determine their gender, unless you are highly experienced and have a more in-depth insight into their specific characteristics. You may only assume whether it’s a male or female and name it accordingly. However, the fish may surprise you anytime either by laying eggs or not and ruling out your prediction straightforwardly.

It is when knowing the gender of your goldfish is very important. It will prevent accidental breeding and ensure that things in the tank will run as per the plan. Also, the kids can name the fish as per its gender and won’t regret that their female goldfish was once named Tom. It is essential if you are petting the goldfish for breeding purpose.

So, how will you determine whether your goldfish is male or female? Well, luckily, this breed gives enough chances to identify its gender. Continue reading to find out how.

Identifying female goldfish

It is very important that you know your fish is female. It will prevent from accidental spawning, especially when you are not into breeding. The two easy ways to identify a female goldfish are the following:

Body Shape- This is one of the criteria which can solve your major dilemma. Females tend to have rounder and thicker body shape as compared to males. You can also identify from a side view wherein a deeper body signifies the girlie characteristics.

Breeding season- If you have failed to identify the gender of your fish in its young stage, look at the truck of the fish during the breeding season. The presence of small bulge on one side may indicate that there are eggs inside. It will make the shape lop-sided or asymmetrical, telling that this colorful creature is female.

Protruding vent- As compared to the male anal opening or the vent, female’s one are rounder and protrude out slightly as soon the breeding season approaches. It will look more like something raised on the abdomen when viewed from the side. Other than this, the anal fins of females are thicker than the male’s anal fins.

Identifying male goldfish

If you want to name your goldfish George, look out for the following characteristics:

Tubercles- If there are small white spots called as tubercles on the gill shields, you can name it George without any worry. This sign is more prominent during the breeding season when these white spots start developing and later fades out. Old male goldfish develop permanent tubercles with time. Apart from gill shields, these tubercles may also develop on the pectoral fins, on the scales of the body and even on the face.

Note: Do not rely only on the appearance of white spots for confirming that your goldfish is male as some of them do not develop tubercles at all.

Body shape- While rounder body shape signifies female goldfish, those with thin and long shape along with stream-lined body tells that it is a male.

Concave vent– If you closely examine the vent, males will have slightly ovular in shape which will be narrow and elongated. Unlike in females where the vent is protruding male’s one will be concave.

Midline ridge- Males have a very visible midline ridge at the underside of the belly. There will be a noticeable raised line that will be running from the back of the pelvic fins till the vent. On the other hand, in females, the midline ridge is faint.

Chasing behavior- Behavior, especially during the breeding season, is the most effective way to identify the male goldfish. A male goldfish will always be seen chasing the female, staying close to her and even nudging the rear to spawn. It is an excellent sign that identifies male and female in the bunch. Other than staying close and chasing, male will always push the female towards a hiding place to forcing her to spawn.

Best time to determine the gender

The most apt time for gender determination is when the fish reaches maturity. It takes about a year for the goldfish to reach the stage when sexing becomes possible, and identification gets easy. However, at the same time, the rate with which the goldfish mature depends upon the species and the sex.

There has been seen a great difference in the time when the male and female show maturity. While some male breeds reach maturity in just 9 months, some may take more than three years.

Note: If you desire to have equal chances of having male and female, get at least six healthy goldfish of the same variety. There are more chances of having at least one different gender in such scenarios.

Difficulties while determining the gender of goldfish

Spawning time is considered the best time to reveal gender. However, at times, even the experts fail to identify it because there are many exceptions. Some major ones that create confusion and may alter the decision are:


No development of tubercles- Some male goldfish do not develop tubercles even when they reach maturity. While tubercles are the identification of male goldfish, some varieties of female goldfish also develop them.

No protruding vents- Some varieties of female goldfish do not have protruding vents, which is a differentiating feature from male.

Body shape- Some varieties in female goldfish naturally have a round shape and thicker scales. It also prevents experts from identifying gender.

At the same time, other than these, if the goldfish is unhealthy, it will not give these identification characteristics properly for gender revelation. For example, if the females are not well-fed, they will not attain round and thicker body shape and remain lean and thin. Likewise, poorly fed males do not develop tubercles or visible midline ridge.

Therefore, if you are using the above identification features to know whether the goldfish is male or female, make sure they are in a healthy state. Moreover, it is advised to use different signs instead of just one to identify gender. Relying on only one feature may give false assumptions.

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