Is your swordtail fry growing up, and you’re confused whether they are male or female? Or, have you been planning to bring home a swordtail lately but do not know how to differentiate male from female? If yes, this article is just for you. It is vital to identify whether a swordtail fish is male or female to maintain the perfect ratio and look after them as necessary. So, how do you identify male and female swordtail fish?
One of the major differences between swordtail males and females is their caudal fins. Swordtail fish got its name from the long elongated tail in the shape of a sword. However, the “swords” are only present in male swordtails. Female swordtail fish lack the sword-like protrusion and have a normal rounded caudal fin.
Likewise, another way to distinguish male swordtails from female swordtails is gonopodium. Sometimes, a male will bloom late and develops the tail sword later in life. In such a case, gonopodium plays the part to identify male and female swordtail fish. The gonopodium is present in male swordtails, whereas female swordtails lack it.
Moreover, female swordtails are slightly larger than male swordtails. Many physical, physiological, and psychological differences can help you identify male and female swordtail fish. This article will talk about all of them in detail. Keep reading!
Differences Between A Male And Female Swordtail Fish
Differentiating a male swordtail from a female might be easiest as the signs are visibly seen. Here are some things you can observe in your swordtail fish to distinguish males from females.
Caudal Fin (The Signature Tail)
As you can see in the picture above, the beautiful elongated tail is shaped like a sword. The tail is what gave the swordtail its name.
The signature tail extension, however, is present only in male swordtail fish. At the same time, the female swordtail fish lack the tail extension. Instead, they have rounded tail fins.
The “sword” has no actual function; it is decorative. However, it is seen that the female swordtails are attracted to males with longer “swords.” Hence, the only sign of the sword-like tails in male swordtails is to attract or impress the females for mating purposes.
Anal Fin (Gonopodium)
After the swords, the second thing to notice while identifying male and female swordtail fish is the anal fins.
As mentioned above, in an adult male swordtail, the anal fin, i.e., the tail fin underside of the fish’s belly, is pointed and works as a sexual organ for penetration. Whereas the anal fin in females are round, and they lack the gonopodium.
In swordtail males, the gonopodium is present in the underside of the belly of your swordtail fish. It is located near the anus behind the pelvic fin.
The female swordtail, on the other hand, has a wide fan-shaped anal fin. Both pelvic and anal fins in females look alike and are triangular.
Gravid Spot
Gravid Spot is a feature that helps you identify the female swordtail fish easily.
The gravid spot is the womb of the female swordtail, where they carry their babies during pregnancy.
The spot is found in the undersurface and bulks up into a square shape when a swordtail female is pregnant. It is darker in color than the rest of their body and is slightly swollen.
The spot is more prominent during pregnancy, but the spot makes the female more prominent and is an identifiable characteristic in female swordtails.
Body Shape And Size
When it comes to the body shape and size of the swordtails, you may think that both males and females grow in equivalent. But certainly, it isn’t true.
The female swordtails generally have a bulkier body than the males. They have a rounded stomach area that makes them look somewhat large. During their pregnancy phase, their belly gets rounder than usual as they carry the young ones.
The maximum growth of these female swordtails depends on their particular species. Yet, they grow a bit large than the males due to their body shape.
On the contrary, the body shape of the male swordtail is thinner and smooth. In addition, they have a flat stomach area unless they get infected from any disease.
An adult male swordtail measures 5.5 inches on average. At the same time, the female swordtails grow about an inch or two longer than the males, i.e., 6-7 inches, depending on the species.
Difference In Color
Swordtail fish are generally colorful, and captive breeding has produced more beautiful, colorful swordtail fish with vibrant colors. However, these colors can help you identify swordtail female from swordtail male.
I do not mean this in the sense that swordtail females are of one color and males of another. Usually, you can see brighter and more visible color patterns in male swordtail fish. Swordtail fish have loud definite colors and come in various patterns. The color and pattern differ in different types of swordtail fish.
On the contrary, the color of the female swordtail fish is a little bland with softer patterns than males. So, if you have to identify males and females from a group, the most beautiful and vibrant ones are male swordtails.
Behavior
Apart from the physical and physiological differences, sometimes the social behavior of swordtail fish can also come in handy to differentiate males from females.
When there are male and female swordtail fish in the tank, the males usually wander around looking for attention from the females. However, I’ve mostly seen them swimming alongside or chasing female swordtails to breed.
Not only that, but male swordtails can be aggressive at times. When they don’t have enough opportunities to breed or are forced to compete with other males in the tank, they can become aggressive.
Female swordtails, on the other hand, are not as aggressive as male swordtails. However, when they are sick or in the middle of a pregnancy, they may become obnoxious.
Females are also unlikely to act like males when it comes to mating. They don’t chase the males as ferociously as they do the females.
Thus, these are some of how you can identify between male and female swordtail fish.
Why Is Identifying Male And Swordtail Fish Important?
It is important to determine the sex of your swordtail fish. Here are some reasons why:
Maintain Safe Male-Female Ratio
The major reason for identifying male and female swordtail fish is to maintain the safe ratio in the tank.
Swordtail fish prefer to live in groups and should be kept in an appropriate ratio to ensure the safety of female swordtail fish. For example, it would help if you kept swordtail fish in a group of four to five with a larger number of females than males.
The correct ratio of male to female swordtail fish is 1:3. Swordtail males will want to mate continually. In such a case, if you have only one female together with the male, the male swordtail will chase around and harass the swordtail female, causing stress.
You should avoid keeping swordtail males together as they will try to assert dominance and fight with one another.
Therefore, identifying the genders of swordtail fish is important.
To Prevent Or Pursue Breeding
Swordtail fish are prolific breeders and will breed efficiently without any initiation from the owner. If you have mixed genders together in a tank, swordtails take no time to mate and reproduce.
So, if you do not want your hundreds of baby swordtails to populate your tank, you should separate the male and female. For this reason, identification is important.
On the other hand, if you are a serious breeder and keep two male swordtails or two female swordtails together in the tank, the breeding can never occur. For this reason, differentiating male swordtails from females is vital.
To Reduce Male Aggression
If you do not identify male or female swordtail fish while keeping them together, you might end up with two swordtail males together. The problem with this is swordtail males are territorial and aggressive.
Thus, if you identify the gender and place swordtails in the proper ratio will prevent swordtail aggression.
Therefore, for these reasons identifying the sex of your swordtail fish is significant.
Can Swordtail Fish Change Gender?
Unlike most other fish, Swordtails have a more complicated sex determination process since their sex is determined by the temperature at which they are born rather than their chromosomes.
They belong to a group of fish known as protogynous hermaphrodites, which means they can change gender.
Swordtails begin as one sex and transform into another. This is a fairly regular occurrence in swordtails.
Can I Keep An All-Male Swordtail Tank?
You might believe that maintaining just male swordtails in your tank will help you avoid overcrowding. Male swordtail fish are more brilliant and colorful than female swordtail fish, and they will add beauty to your tank.
However, overcrowding your tank with male swordtails has its drawbacks. Male swordtails are aggressive and territorial. The powerful bully the weak swordtails because they live in a hierarchy. Alternatively, to keep the fight balanced by nipping and biting each other.
Your swordtail’s health and immune system will suffer as a result of this. As a result, it would be preferable if you did not keep an all-male swordtail tank.
Can I Keep An All-Female Swordtail Tank?
When you keep an all-female swordtail tank, you’ll be making a wise choice. This is because female swordtails are less aggressive than male swordtails. Female swordtails can also coexist nicely with other community fish.
But there’s a snag. Female swordtail fish may store sperm for several inseminations in their bellies. As a result, an all-female swordtail tank runs the risk of becoming overcrowded with swordtail fry at some point. But, of course, you can avoid this if girls and males are separated as soon as they are identifiable!
Females, as I already stated, are docile. However, if there are weaker fish nearby, they can become bullies. After all, hierarchy is a natural phenomenon.
FAQs
Here are some related questions.
At What Age Can You Tell If A Swordtail Fish Is Male Or Female?
Since swordtail fish develop their sexual organs between the ages of 4-5 months, you can tell whose gender they are during this time! However, some swordtails are late bloomers and take a long time to grow their pointed anal fins. This is why many people mistake the male swordtail fish for a female.
The Maximum Number Of Swordtails That You Should Keep Together?
A single swordtail fish can be kept in a tank. However, keeping swordtail fish in a group is preferable. So, in your aquarium, you can have 4-5 swordtail fish.
Can Swordtail Females Have Babies Without Males?
Female swordtails have the ability to retain male sperm for months after copulation. Therefore, she will be able to give birth to all of the babies simultaneously in the future, as long as there are no male swordtails in the tank.
It implies that she can give birth to a swordtail fry without the presence of a male. However, it does not imply that a female swordtail may give birth to offspring without mating with a male swordtail.
Conclusion
I recommend that you identify the gender of swordtail fish before keeping them in a group. It aids in maintaining the male-to-female ratio in the aquarium, which keeps the fish healthy.
You can distinguish male and female swordtail fish by their body color, shape and size, dorsal and anal fins, and behavior. These characteristics of the swordtail can help you determine their gender. However, properly examining them takes time and patience. Please don’t rush!
I hope you found this material useful! Maintain a comfortable and safe environment for your swordtail.
