Swordtail fish are generally counted among the most peaceful species of livebearers. Their hardy nature has made them an excellent choice not only for first-timers but also for veteran aquarists. The amicable and un-hostile temperament followed by their unique looks certainly makes it a wonderful addition to your tank, but it is not always the case. They can sometimes fluctuate their nature. So, Are swordtail fish aggressive?
The answer to the question, “Are Swordtail Fish Aggressive?”, is, No. Swordtail Fish are not aggressive by nature. They are peaceful, sociable fish that make a great addition to community fish tanks.
Surprisingly, swordtail fish can sometimes turn out to be aggressive and territorial. They are aggressive eaters. Likewise, the male swordtails chase female swordtails during the mating ritual, and they can be pretty defensive about their territory.
Aquarists with previous experience with the fish might have noticed their aggression and territorial nature at least a few times.
The aggression and territorial nature of swordtail fish follow a lot of causes and consequences. It is natural for swordtails, along with most other livebearers to behave in this manner, especially when their requirements are not met with. Both male and female swordfish have their reasons for exhibiting such behavior. However, males are more prone to react in this way (more on this later).
This article will dig deeper into what may lead the calm and friendly fish to choose the path of violence.
Why Do Swordtail Fish Chase Each Other?
The foremost reason why swordtail fish chase each other has to be the mating ritual which involves attention-seeking. Similarly, the chasing also has to do with their territorial nature.
A male swordfish will go around chasing the females to choose their mating partner. They also tend to aggressively chase and fight other males in the tank to get the female. Although this act might seem like an act done out of aggression, this is not uncommon and does not cause any harm.
However, the constant chasing and harassment can stress the female fish. If the ratio of male to female is not maintained, it can lead to female fish being exhausted. They may hide among the plants, other tank decors, or may sit at the bottom.
If you see two male swordtails chasing each other, it is usually to assert dominance and to protect the territory from intrusion. Even if your tank does not contain female fish, male fish are sometimes seen chasing each other. This usually happens as the alpha male or the stronger male tries to peck order at the weaker fish.
Unless the chasing is followed by fin or tail nipping, there is nothing to be alarmed about. But, if you see your fish fighting and nipping, you should take some precautions.
Proper aqua scaping and plenty of space are recommended to prevent these fights. The heavy plantation provides the weaker males and females to hide from their oppressors. And, plenty of space allows the fish to mitigate stress.
Are Male Swordtails Aggressive?
No, male swordtail fish are not generally aggressive. However, they can exhibit aggression while feeding, mating, and protecting their territory.
If you have more male swordtail fish, certainly you have witnessed a lot of fighting. Two males can fight each other to decide on the stronger male in the tank. The stronger male is seen dominating the weaker male. Likewise, the alpha male also tends to demarcate their territories in the tank and become hostile to intruders.
Swordtail males also show their aggression during feeding time given that they are aggressive eaters. Therefore, you must provide enough food for everyone in the tank periodically.
Further, this kind of chasing and nibbling behavior can be seen at the time of mating. Swordtail males chase female swordtails to mate with them. They also chase and fight with other male swordtails in the tank to gain attention from the female.
Avoid keeping two male swordtails in the same tank to prevent unhealthy competition between them. Similarly, you must keep more females than males to protect female fish from endless chasing and harassment.
Why Do Male Swordtail Fish Fight?
Although swordtail fish are generally considered peaceful amicable fish, fights can be seen between two male fish. As discussed previously, the fights usually occur for their male privileges: strength, female, and territory.
In a male-only tank, or tanks having more than one male swordtail, a fight is likely to sprout. They fight and chase each other in the hustle of dominance. The weak are always preyed upon. Male fish also tend to fight each other in front of females as mating requires seeking attention from the female swordtails. Likewise, the males are overly protective of their territory.
Aggression can lead to fighting which usually includes fin and tail nipping. The injuries can lead to severe infections, even causing deaths.
This problem can be solved by not keeping more than one male in a tank or introducing more females to the tank.
Are Female Swordtails Aggressive?
No, like males, they are also not aggressive. However, pregnancy and stress can opt them to act relentlessly.
While pregnant, female swordtails tend to limit their movements. They hide among plants when they are trying to spawn. The additional weight can be stressful and slight interruption and disturbance might annoy them which can lead to hostile behavior.
The aggression can be seen exhibited more during the time of feeding. Females may end up fighting other fish to get the food she needs during times like this.
Female swordtails are also aggressive if their tank is overcrowded. They are active swimmers and scarcity of enough breathing space can annoy them.
Aggressive Behavior Among Swordtails
You can figure out if your swordtail is getting aggressive through its behavior with other swordtail fish in the tank. How does an aggressive, bully swordtail fish act?
An aggressive swordtail fish tends to chase other innocent and timid swordtails in the tank. These bullies usually demarcate their territories in the tank. And they try to fight with whoever tries to invade their space.
If you have more than two or more male fish in the tank, they are likely to compete with each other to get the attention of the female swordtail in the tank. The other reason for aggression, therefore, is for mating purposes.
Aggressive Behavior Between Swordtail And Other Fish
Swordtails are sometimes seen picking on other species of fish in the tank too; be it smaller fish or even larger fish than themselves.
When swordtails are usually interactive and amicable with other species of fish, they can show aggression to other fish followed by chasing or nibbling on their fins and tails. The reason behind this could again be the space.
Swordtails are active swimmers, they like to explore around the tank and are more likely to form their territory. So, if other fish verges on entering their territory, they are more likely to show aggressive behavior.
That said, the chasing and nibbling do not always mean that they are attacking. These acts are a normal playing/ mating ritual. Unless the fish cause damage to other fish, there is nothing to worry about.
Causes Of Aggression
So, what makes these fish show aggression in the first place? Listed below are some common possible causes:
Overcrowded Aquarium
The immediate cause could be inadequate surroundings. While swordfish can adapt to a wide range of tank environments, they still have some basic requirements. Disturbances and scarcity in their habitat can be one of the main reasons for their aggressivity. An overcrowded tank will limit the swordtail fish’s exploration, which might cause stress, which in turn can change into aggression.
The solution is to keep limited fish in your aquarium. Swordtails are active and excellent swimmers. Providing them enough space to swim will only do them good.
Male To Female Ratio
If you have more males in the tank, there are ultimate chances that they will fight each other. When there is competition for females, the males do turn impulsive. You can introduce female swordtails in the tank to reduce this behavior. Because, like everywhere else, females help maintain peace in the fish world too.
Similarly, if you have more male than female, or one male to one female, chances are your male swordtail will harass your female swordtail.
Hence, you must check your male to female ratio. The appropriate ratio is 1 male to 4 female swordtails. This will eliminate all unhealthy competition between males and females are also safe.
Spawning
Aggressive behavior can be seen in female swordtails during their pregnancy. We should put it out here that it is more of a stress than aggression. The stress, as mentioned above, leads to frustration and aggression.
The solution to this is separating the pregnant female into another tank for feasible spawning. This helps reduce her stress and you will also be able to protect the juveniles.
Fluctuation In Water Perimeters
If the water conditions in the tank are not favorable, your fish will become stressed and turn out to be violent. Swordtails much flourish in warm water with temperature ranging from 65-80F, and hard water 12-30dGH.
Fluctuation in these conditions can push these organisms past their peaceful behavior. Regularly test your water to eliminate the chances of your fish turning into an assassin.
Inadequate Diet
Swordtail fish are aggressive eaters. That is why you need to make sure there is an abundance of food available for them. If they don’t get enough food they can start acting aggressively.
It is recommended that you feed your swordtails at least a couple of times a day with supplements that are rich in both proteins and fibers. This will reduce their hostility to some extent.
How Can You Tell If They Are Fighting?
Aggressive behaviors like chasing and nibbling on other fish are a part of the general playing/mating ritual. Serious fighting comes with distinctive behaviors. Here are some:
- You can see damaged or nipped fins.
- The weaker fish will normally hide in aquarium plants or ornaments and tend to be isolated a lot when bullied.
- There is constant badgering and chasing that is aggressive.
- A fish has died not of natural reasons or faulty water parameters.
If you observe any of the above-mentioned actions going on in your tank, be aware that it is due to bullying. Identify and separate your oppressor as soon a possible.
Can Swordtail Fish Kill Each Other Or Other Fish?
Yes. rarely, but there are cases when swordtail fish will kill each other or other smaller weaker fish in the tank.
There are chances that you are keeping a dominant alpha male in your tank who shows aggressive behavior all the time. Such fish will try to traumatize all the smaller weaker fish it can find. The weakfish can be an outnumbered female, sub-male, or a new addition to the tank.
The aggressor might chase or harass the weakling to the point that they get severely stressed; leading to death.
When swordtails nip at the fins of other fish, bacteria and parasites can get into the body introducing the injured fish to deadly infections.
So, it is possible for the swordtails to sometimes kill each other or other smaller fishes. However, this is very unlikely and you should not be much worried about it.
Do Swordtails Eat Their Fry?
Yes. If you do not take care of the juveniles, the parents will likely is likely that the parents will feed on their off-springs.
Swordtail fish, like most livebearers, lack parental instincts and confuse their fry for food. Therefore, you must take safety measures to ensure that the babies are safe until they get big enough.
To protect the fry from their parents, you can:
- Separate pregnant females at the time of spawning
- Put live plants in the tank to provide safe hiding places
- Get a separate breeding box
- Remove the adult fish after giving birth and keep the fry separate until they are big enough to not get confused for food,
Are Swordtails Fin Nippers?
Swordtails are not generally the fin nipping kind because they are a peaceful species. But, they can sometimes act on it out of aggression during fighting or mating.
They try to nip fins and tails of other swordtails or any other tank mate. But it is not drastic. However, you must give your utmost attention to the fish with injured fins and tails as it can invite infections.
Likewise, to prevent this from happening, eradicate all the possible reasons that can lead the fish into fighting (like maintaining a 1:4 male-female ratio, an abundance of food, single male in a tank, enough space, and as such.)
What To Do About An Aggressive Swordtail?
Even after you separate the bullied fish, there are chances that the aggressor will make another victim. Therefore, it is best if you separate the aggressive swordtail into a single tank.
Keep it alone for a couple of days and see if it calms down. If it still causes trouble after being separated and re-adjust into its primary tank, then it is time to wave your fish goodbye to prevent further injuries in your aquarium.
What To Do With Bullied Swordtail Fish?
If bullied swordfish is be showing signs of injury or infections, you should probably shift to a separate tank to spread infections to other tank mates.
Put your fish into quarantine and closely observe and take care of them to prevent further infections. Apply medication or seek a vet if the injuries are severe.
Conclusion
Aggression is not a common fish trait, not a trait in livebearers even more so. You can only see these sorts of aggressive behaviors when the fish are not content.
If you take care of all the basic requirements of your swordtail, chances are you will never see their toxic traits.
Swordtails are the most peaceful and amicable species of fish you can find. The aggressivity is an extreme behavior these fish portray. So, do not let it discourage you from keeping swordtails. They can be a wonderful addition to your tank.
