Why is my Swordtail Fish Hiding?


Swordtail Fish Hiding – Wojciech J. Płuciennik (CC BY-SA 4.0)

If you need a colorful, easy to breed and peaceful fish to add in your aquarium, swordtail fish is a great consideration.

Swordtail fish is native to Central America and North America and their crossbreeding has led to the production of many fin shapes and colors.

One of the fish that has resulted from the crossbreeding is the Lyretail, which features a lower and upper sword. Some of the other varieties boast high fin dorsal fins too.

The original swordtails are the Green swordtails, which are olive-green on their upper side and yellow-green sides with dark-brown edges.

Swordtails are amazing and in addition to their beautiful colors, they are easier to breed and peaceful. However, sometimes the fish exhibit some unusual behavior that is very hard to understand. One of these unusual behaviors is hiding inside the aquarium tank.

So, what causes swordtail fish to hide? Swordtails will hide if there are issues with the water quality, during pregnancy labor, when ill or just because they are scared.

To help you track the main causes of their hiding, we will look into every cause. I will also provide you with tips on how to solve issues. Here are the main causes.

Disease or Parasites

Swordtails are exposed to various diseases and parasites, which occur at water surface constantly. All species of fish are subject to bacterial, disease-causes viruses and fungi infections. Tapeworms, nematodes, trematodes, lice and leeches are likely to parasite the fish.

In aquariums, the organisms occur at very low levels and may affect a small number of swordtails. Some of the things that characterize infected fish are sterility, slow growth, stunted population and high mortality rate.

Fortunately, parasites and fish diseases are unlikely to reach epidemic levels and they are rarely the cause of most deaths in aquariums. A swordtail fish suffering from parasites or diseases dies slowly and you might lose several fish in a day.

But if the fish are in starvation, poor condition, injured, overcrowded, stressed, mixed with the wild fish or the levels of oxygen are low and temperatures are high, the parasites and diseases will become a serious threat.

Mostly, the affected fish show visible discoloration, sores, bleeding, popeyes, lumps, white or black spots and abnormal growth on the fins and head. The sick fish will act and look abnormal and may hide most of the time.

You can use controlled methods to treat the sick fish. Stock only healthy swordtails and exclude any wild fish from the aquarium.

Bad Water Quality

Water quality is important for the success of our aquarium and if it is very poor, your swordtail fish will pay the price. Nitrite and ammonia are two of the commonest problems you will encounter when caring for your swordtails and the two are harmful.

Some of the things that lead to ammonia are a build-up of fish waste, failure to remove the dead fish promptly and allowing the leftover food to rot at the bottom of the aquarium. Avoid overfeeding the fish if you would want to maintain the best water quality. That way, your fish will not hide anymore.

Female Swordfish is Ready to Give Birth

The hiding swordfish might be pregnant. You can spot a pregnant swordtail fish easily because it will have a swollen belly and feature a gravid spot. In pregnancy cases, the hiding behavior is perfectly normal and you should not worry about losing the fish.

When the time of birth is near, the swordtail will start acting territorial and hide in plants or the decorations as a way of protecting the fry. After the swordfish gives birth, it will return back to normal behavior.

To protect the newborn fry, transfer it to a different tank or buy breeding traps to keep the adult swordtails because they are known to eat their babies.

Stress Due to Bad Tank Mates

Surprisingly, swordtails become stressed easily just as man does and that can affect their health adversely. A swordtail that is more stressed is likely to catch diseases and will struggle more to fight the common illnesses off.

Stress mostly results from disturbances of noise, substrate changes, placement of hands in the fish aquarium and bullying from the other fish. Therefore, you will have to avoid disturbing the swordtails at all cost and ensure that any fish species you plan to add to your aquarium is compatible with the swordtails.

Some fish species cannot live in harmony and mostly, you will find one species chasing the other around the aquarium. Some may nip the other fins. As a result, you will realize that most of the fish are hiding.

Improper Male to Female Ratio

Swordtails are known to breed faster than many other fish species if the males dominate. The males harass the females and try to mate with them severally. That is the reason you will have to maintain healthy males to female ratio in your aquarium.

If the ratio is not optimal, the result will be illnesses and distress. That is because the male swordtails are known to dominate the aquarium.

Ensure that the ratio of males to females is 1:3. Failure to do that, the males will end up chasing and harassing the females until they start hiding and finally die. If the males are in domination, the females will not get any resting chance.

You can also set the ratio according to the breeding rate that you desire. The rate will highly increase if the ratio is 1:1. If there is no breeding, you should know that all the swordtails are either males or females. Depending on the size of your aquarium, you can maintain a larger school to prevent the problem.

Other External Factors

The swordtails might be afraid if the tank is inside one of your busy rooms with predators like cats or flashy lights. In fact, those are some of the factors known to stress the fish and influence them to hide – both day and night.

You will have to remove any disturbing factors around the tank and check how the fish behaves. You are likely to notice that they will stop hiding.

If your swordtails are free from the above, then they are just shy or scared. Usually, people count swordtails among the large live-bearers and other fish species do not intimidate them easily.

However, if you have stocked some of the large fish species in your aquarium or more males than females, the swordtails might be scared of the aggressive behavior of the males. That might influence them to hide.

How to Keep Swordtail Fish Healthy?

Swordtail fish are popular due to their peaceful nature and ease of care. The fins of this type of fish are unique and come in various colors, which make them referred to as Green swordtails or Red swordtails.

Today, people are also breeding them to achieve some other colors and that is the reason you are likely to find many other types. For them to remain healthy, remember to filter the water properly. By setting the filtration system in the right manner, the water quality will remain high.

When it comes to feeding, the swordtail fish accepts a wider range of foods. Provide them with higher quality live foods such as daphnia, mosquito larvae, brine shrimp, bloodworms, fruit fries and flake foods. They eat virtually anything.

When in their natural habitat, swordfish consume algae and other vegetation, which means that you should not neglect the need for herbivorous food. Keep the mix of vegetation and protein optimal.

What Fish Can You Keep With Swordtails?

Swordtails are more active than other fish species but they live peacefully and get along well with other species such as mollies, Corydoras, platies, tetras and angelfish

However, there are restrictions with tetras and Corydoras and that involves keeping them in larger groups. In addition to that, you will have to get tetras and Corydoras that can live peacefully.

Keep the number of males lower than that of females to reduce the chances of stress. Males are known to get agitated quickly.

What is the Best Aquarium Size for Swordtail Fish?

Swordtails are strong swimmers and therefore you will have to invest in large aquarium tanks. On average, you should buy a tank of 10 gallons capacity for each swordtail and a good aquarium should have enough swimming space in addition to many plants.

The tank should also feature a hood to prevent the chances of the fish jumping out. You are not limited to the number of swordtails you can keep in one aquarium if space is adequate and every fish is comfortable. However, the male swordtails are likely to be territorial and they can fight the other males in your aquarium.

So, regardless of how beautiful the males might appear to be, you should not fill them in your tank.

The size of a swordtail fish can be large. The males can grow to around 4 inches (11cm) while the females can attain 5 inches (12cm) length excluding the length of their tail. However, when in small tanks their size can be smaller.

Their lifespan is 3-5 years. If you are planning to get many swordtails, you will need an aquarium tank that can hold around 30 gallons of water.

Swordtail Fish   Updated: October 7, 2019
avatar Hey, I'm Fabian, chief editor at Aquarium Nexus. I really enjoy the aquarium hobby and love sharing my experience with others. If you have any questions feel free to contact me or leave a comment below.

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