3 Crucial Tips On Taking Care Of Swordtail Fish Fry

If you need help on how to take care of a swordtail fish fry, I have 3 easy-to-remember tips for you. Young fries are very vulnerable, and if you want to keep most of them alive until adulthood, it’s crucial to learn their behavior and that of the parent fish after giving birth. I will give you the key to organizing the tank and providing nutrition to swordtail fries. I will also reveal the truth about some myths relating to this fish specie.

Characteristics Of Swordtail Fish Fry

What do fries swordtails look like? And how do they behave? Having the answers to these questions will make fish care easier. I will give you the details.


Even during the fry phase, a swordtail has different states of development to go through. A new fry is tiny and only 1/4 inch long on average. But when it matures enough, which is at the end of the fry phase and the beginning of the juvenile stage, it can vary from 1.5 to 2 inches in length.

A fry can more or less take care of itself. The young ones feed without needing help from adult parents, and they can find their own hiding spot if we provide them with one.

What do fry swordtails look like?
What do fry swordtails look like?


It’s sad, but it’s true that not all fries will make it out alive, and it’s our responsibility to separate the sick from the healthy ones to avoid disease development in the entire tank. And how do we know if swordtail fries are healthy or not? The swimming pattern, activity, and food consumption are aspects we must consider.

If a fry has a weird swimming pattern due to stress, it will move around without seeming to go in a certain direction. Its reaction also is significantly reduced, so it tends to hit its head against leaves, branches, tank walls, the bottom of the tank, etc., more frequently.

An unhealthy fry may have clamped fins, a condition where a fish aligns its fins against its body instead of spreading them into a fan-like shape. The sign is highly perceptible, and it usually indicates the invasion of parasites. You have to quickly remove young fries with parasites to protect other fellows.

If your swordtail fries don’t eat properly and lay at the bottom of the tank without moving much, this also is a sign that indicates sickness.


Due to their size and strength, swordtail fries can’t fight back if juvenile or adult ones act aggressively. They frequently find shelter under big leaves or “caves” made of decorative rocks to protect themselves. Juvenile and adult swordtails spawn in open space more.

3 Crucial Tips To Take Care Of Swordtail Fish Fry

I have 3 easy-to-remember tips for you if you are about to welcome dozens of swordtail fries into your tank.

Separate the fries from adult swordtails

Adult swordtails, especially the females, tend to feed on the young ones if owners don’t provide them with enough food. Also, this fish species don’t have a maternal instinct, which explains why they eat the fries when they are still small.

In this case, it’s best to separate the fries from the adults to avoid a massacre. Put the fries into a different tank soon after birth to have more space and better condition to grow in size. When they are too big for other adult fish to attack and swallow, you can unite them in a join tank if that’s what you want.

Adult swordtails
Adult swordtails

Add hiding spots into the tank

If you provide them with enough food and prefer keeping fries and adults in the same tank, I recommend you provide the young ones with many greens as hiding spots. They can proactively protect themselves from aggressive tank members by taking advantage of big leaves and using them to shield themselves from predators’ eyes.

Choose a big tank

The same rule applies to both young and mature swordtails. A big tank that is cycled frequently and is clean will ensure healthy development. Also, if you want to keep a good number of swordtails in the same tank, having too many males compared to females will increase the level of tension between the males. So you have to keep a safe male: female ratio.

Male swordtails fight when there isn’t enough chance to breed with female fellows in the tank. And the fights are likely to cause stress among other members, including young fries. If you want them to reach adulthood, I highly suggest you pick a giant 50-gallon tank for about 20-23 swordtail fries.

5 Common Foods To Feed Swordtail Fish Fry

There are more options, but by far, these are my top 5 best foods for young fries since they are small enough for them to consume without extra preparation.

Vinegar Eels

For an even more accessible live food supply, you could also feed your fish vinegar eels, larval worms that grow in vinegar. They are relatively cheap options, and they are alive, which ensures the freshness of quality since they can survive in the tank for a few days.

Brine Shrimps

Not just any brine shrimp but baby brine shrimp. They should be small enough for swordtail fries to consume whole. If you pick non-living brine shrimps, make sure to keep them in a refrigerator to maintain the nutrition and avoid the formation of bacteria.

Larvae Of Mosquitoes

Larvae of mosquitos contain lots of protein and added supplements like vitamins or minerals. They help a lot in color development.


Daphina contains vitamins A and D, which aid the coloration and the immune system of your small fishes. It’s easy to get and not expensive either.


Duckweed is a natural food source that contains vitamins and protein. It multiplies using only air and water, and the best part is that it leaves the tank clean.


Do swordtail fish consume their fries?

Yes, especially the females since they don’t have a maternal instinct. Typically, they give birth to about 10-50 fries, but not all of them reach adulthood. The reasons can be diseases or attacks from parent swordtails.

Why is my swordtail fry dying?

Due to being small and vulnerable, swordtail fries may not survive an unideal tank environment. If the tank isn’t cycled or the water condition isn’t clean, many will die off before reaching adulthood.

How many fries do swordtails have?

Swordtails can give birth to as few as 5-10 fries to as many as 100 fries. Each pregnancy is different, and it’s hard to follow the exact number since baby fries are tiny, and most of them will hide if there are greens in the tank.

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