Swordtail fish “Xiphophorus helleri” is a common fish for community aquariums. They come in various exciting colors and create a colorful pool full of unique colors. Aside from their bright appearance, they are loved by many aquarists for their peaceful nature.

In this article, we will explain in detail all you need to know as one who wants to be a proud owner of this colorful fish. All possible questions like its tank size, feed, fish mates, breeding, care, etc., will all be answered.

So, kick back and relax. You’ll enjoy this read.

Swordtail Fish Statistics

Quick stats:

Origin North and Central Africa
Temperament Peaceful
Lifespan 5 Years
Diet Omnivore
pH 7 to 8.3
Hardness 12 to 30 KH
Temperature 64 to 82°F
Minimum Tank Size 20 Gallons
Average Size 5.5 Inches
Care Level Beginner


Order: Percopsiformes
Suborder: Cyprinodontoidei
Family: Poecilidae
Genera: Xiphophorus

Origin of the Swordtail

Swordtail fish can be found mainly from Mexico to Honduras in North and Central America. You can see the majority of them in Belize, Guatemala, and Mexico, predominantly in freshwater. They favor rivers and streams surrounded by vegetation.

The freshwater swordtail fish has a high tolerance for a wide variety of water conditions and a peaceful disposition. For these reasons, the swordtail fish is an excellent choice for beginning aquarists.

– Appearance

Most swordtail fish have a base color of olive green. The olive green color is punctuated with a reddish-brown line that runs down the entire length of their body. In captivity, you will see even a broader range of colors adorning the swordfish, all thanks to interbreeding.

The swordtail fish’s most distinguishing feature is perhaps their caudal fin that protrudes down the lower half of its body, creating the impression of a sword. Yes, that is why they are referred to as the ‘swordtail fish”.

We will further distinguish between the male swordtail and the female swordtail fish. The distinction will come in handy when it’s time to condition them for breeding.

– How Can I Differentiate Between the Male and Female?

The male’s caudal fin protrudes along the lower half of his body, reaching as much as half the length of the entire body. There is no protrusion on the caudal fin of the female. Thus, it is pretty easy to differentiate between the sexes of this species.

Another distinction is the size. Male swordtail fish are generally smaller than females. Sometimes, the difference in length could be more than an inch.

– Size

The average swordtail fish size is 5.5 inches. The male swordfish, however, is a tad smaller than the female swordfish. With proper nutrition, your fish can grow longer than this estimated size.

– Average Lifespan

The average Swordtail fish lifespan is four to five years. They are livebearers, which means that giving birth can be quite taxing on their tiny bodies. Due to the exertion, they become more lethargic, and their colors become dull as they age.

Swordfish Fish Care

The truth is that caring for the swordtail fish is not as tasking as caring for so many other fish species; it is relatively simple. They are full of life and varying colors, so they make your tank beautiful and lively. For a beginner in the fish-keeping world, this is a perfect place to start.

To care for this fish, you must try to replicate the conditions in its habitat. Of course, not everything can be replicated, but there are a few that are crucial. You will find them below.

– Creating the Optimum Environment

Swordtails flourish in densely vegetated streams of flowing water. You can also find swordtail fish in small ponds, drain pipes, and vents. They can also tolerate brackish water so that they can be held in low-salinity environments. Their hardiness, which allows them to live in a wide range of conditions, is one factor contributing to their popularity.

  • Tank Size – Swordtail fish are medium-sized fish that, on paper, don’t need a lot of space. However, they’re hyperactive; thus, they benefit significantly from having enough room to swim around. A minimum tank size of 15 gallons is needed for one adult swordtail fish. However, if you want to add more fish for business, you’ll need at least a 29-gallon tank.
  • Temperature – Swordtail fish are tough tropical fish that can survive in a variety of water temperatures. They should be fine in water temperatures ranging from 65 to 82 degrees Fahrenheit. Despite their adaptability and durability, avoid sudden and violent temperature drops, as this can damage your fish and make their immune system vulnerable.
  • Water Hardness – Swordtails prefer very rough water with a hardness of 12 to 30 dGH
  • pH – The swordtail fish thrives at a pH of 7.0 to 8.4. They prefer mildly alkaline, hard water in general.
  • Filtration – Make sure the water is adequately filtered at all times. The water parameters will remain high if you set up your filtration device correctly. Always keep track of water parameters so you can respond quickly and avoid potential problems.

– Tank Mates

Swordtail fish are a calm and energetic species. They are very friendly and enjoy being in the company of other swordtails or related passive animals. They prefer swimming in the middle and upper part of the tank.

It is essential to consider the swordtail fish compatibility when selecting tank mates for this fish. When kept with boisterous fish, swordtails may become shy and hide among the plants and decorations. Similar relatives, such as platies, mollies, or angelfish, will make excellent companions for the swordtail fish.

Other tank mates include:

  • Corydoras that are peaceful make excellent companions.
  • Some of the larger tetras can be fantastic but endeavor to keep them in four or five schools to avoid such harassment.
  • Other suitable organisms would be easy to find; the tricky part will be choosing between them. You might combine them with Rosy Barbs, Dwarf Gourami, Pearl Danio, or Angelfish in the mid-levels of the tank.
  • Kuhli and Zebra loaches are good choices for bringing some life to the lower levels of your aquarium.

Tank Mates to Avoid

Aggressive species that can strike and kill your swordtails should be avoided at all costs. This eliminates the majority of Cichlids. Remember, the aquarium aims to mimic the natural state of their original habitat, and there, they never come across aggressive species.

Now that you’ve had a good knowledge of their suitable tank mates, let’s look at their best tank size and grouping.

What Ratio of Female To Male Should I Have in My Tank?

One male to three or four females is the best male-to-female ratio. As a result, males will not abuse females excessively, as the violence will be fairly distributed. Since swordtails are excellent jumpers, consider protecting your aquarium to avoid suicide attempts.

– Diet

Swordtail fishes are omnivorous thus, selecting what they can eat is not a challenging task. Mimic what they eat in the wild. They would eat insect larvae, algae, and other plants as part of their omnivorous diet in the wild.

Thus, we advise that you provide them with a variety of nutrients in the form of high-quality dried foods.

  • Greens – Make sure they have some greenery (vegetables) as well (this will provide some fiber to ease their digestion).
  • Algae – Algae wafers are an excellent option, but you might also use some green vegetables that you already have on hand.
  • Protein – It is tempting to settle for feeding your swordtail fish with only greens. However, as juveniles, they need a lot of proteins. Thus, we advise that you add live or frozen foods such as bloodworms, daphnia, and brine shrimp are essential additions to their dried food diet.

a) How Often Should Swordtail Fish Be Fed?

Swordtails should be fed twice a day. They only need a small amount of food, which they will consume in a matter of minutes. Excess food only results in overfeeding for them, which causes them significant levels of stress.

They’ll quickly learn when to expect food if you stick to a schedule, and they’ll become much more active during feeding times. Remove any food that hasn’t been consumed so that it doesn’t decompose and pollute the water.

b) What Happens When I Don’t Stick to the Feeding Schedule?

Now here is a thought, “What if I get too lax with my fish care protocols? What if I don’t pay proper attention to their feeding? Well, I have an answer for you. They drop their immune levels. Then what?

Opportunistic pathogens can invade their system and possibly cause disease. We don’t want that now, do we?

We will still look at some possible diseases and their solutions.

– Breeding

Breeding may begin as early as the third month of life, so you should segregate swordtails after sex determination. During the breeding season, males will swim alongside females, sometimes nipping them. Females may become stressed due to this, so there should be more females in the tank than males.

When a female is pregnant, her belly swells, and a dark gravid spot appears near the anal fin. As their bellies grow larger, they begin to avoid the male swordtail fishes and may even become more aggressive. A pregnant female will hide in a corner and restrict her movement to the hiding spot.

Swordtails are livebearers, which means that after the eggs have matured in the female’s body, she gives birth to live young. It may take longer to get pregnant again, and it may happen even if there isn’t a mate present. That is because swordtails will store sperm cells in their pouch and fertilize themselves regularly.

a) How to Condition Swordtail Fish for Breeding

Certain factors help induce breeding in swordtail fish. You must set the ideal temperature for breeding in place; warmer temperatures are recommended. Other parameters such as kH, pH, ammonia, nitrites, and nitrates should be monitored and maintained at safe levels.

You will inspire them to breed by doing a few things:

  • Raising the water temperature to 80-82°F gradually
  • Maintaining cleanliness as possible in the tank
  • Providing them with a balanced diet, especially proteins

b) How Many Fry Do Swordtail Fish Breed?

Swordtails can produce 50–100 fry each time they mate, and they can breed again four to six weeks later.

c) After Breeding, What Next?

Swordtail fish eat its fry because it is normal for them to do so. The remedy is to ensure that they are well-fed when they approach their due date. It would be best if you fed them twice a day. As soon as you see the fry swimming, pull them out and place them in another tank. Since the fry is too small to consume adult feed, crumble some flakes or buy some refined foods.

– Common Diseases

An ectoparasite causes ich (also known as white spot disease). It presents as white spots to appear on the body or fins. Boost the temperature to 82°F and add one teaspoon of salt per 2 gallons of water to treat it.

Mouth fungus, also known as cottonmouth because it produces fluffy growths around the mouth and fins, is another possible disease. Antibiotics from a pet shop can be used to treat this.

If you see signs of disease, put the infected fish in a quarantine tank to keep it from spreading to your other fish.


  • Swordtail fishes are peaceful, calm, and energetic fish species
  • They have fascinating caudal fins shaped like a sword
  • Swordtails are live breeders and can produce up to 100 fry in a single breeding session
  • They are hardy but prone to cotton mouth disease and other freshwater diseases

Swordtails are a perfect addition to any aquarium that contains a variety of peaceful freshwater fish. They get along well with other fish species but can become stressed if their tank mates are hostile. You should have few issues if you keep the tank clean and maintain its desired conditions.

5/5 - (18 votes)


Please enter your comment!
Please enter your name here