Swordtail Fish – Diet, Care, and Breeding

A very popular species of aquarium fish, the swordtail fish is a great and common choice for the beginner aquarist. They are known to be tolerant to a wide extent of atmospheric conditions and are characterized to have a very peaceful temperament.

It goes without saying that the swordtail fish has a long, thin, elongated lower tail. Swordtails are also livebearers, meaning their way of giving birth is not through laying eggs but through live young or fry. They also readily breed when they are kept in the aquarium of mixed sex which makes it easier for there is little intervention needed. The young are very easy to nurture as they can be raised in the same aquarium along with the adults.

There are a number of varieties of swordtail wherein the most popular is the solid orange variety – typically found in most fish stores. Other examples of swordtail fish include Red Velvet Swordtail, Red Wag Swordtail, Neon Swordtail, Pineapple Swordtail, Black Nubian Swordtail, and Marigold Swordtail. When it comes to the decorative nature of the fish, the male swordtail owns the bigger price than that of the female.

Swordtail Requirements:

Temperature – 64-82F

pH – 7.0-8.3

Hardness – 12-30 KH

Max Size – 4 inches

Minimum Tank Size – 20 gallons

Diet- Omnivore

Care Level – Easy

Temperament – Peaceful

Cost – $4.49


Swordtails Notes and Facts

Swordtails are commonly found in the wild warm waters of Mexico and traverse much of Central America. They thrive in flowing streams with dense vegetation which is why they can also be found in small ponds and even in drainage pipes and vents.

As mentioned earlier, their tolerance to different conditions, even when in captivity, is quite impressive. This is why swordtails are a great beginner fish. The male swordtail can grow up to 6 inches. On the other hand, the female swordtail grows approximately 5 ½ inches. However, these lengths are uncommon due to the fact that fish stores usually sell swordtails that range from 1 to 2 inches in length. If you are planning to keep swordtails so they can grow to their, at least, maximum lengths, you must own a larger tank than usual.

Swordtail Breeding & Fry

One of the main reasons that swordtails are considered to be a great choice for beginner aquarists is because they are livebearers. They give birth to live young. Swordtails are excellent fish to practice breeding because they require little to no intervention from the owners. They often breed on their own. The young they produce are free swimming and relatively large when born, both of which gives them a higher chance of growing to adulthood than those fish raised from eggs.

NOTE: There should be MORE FEMALES in the tank if you intend to breed swordtails. 1 male to 3 females is usually recommended for higher chances of success.


During mating, the males will continuously swim next to nip the females, which will cause the females to be stressed and exhausted. This is the reason why females should outnumber the males in an aquarium. Not only to accommodate the male swordtails but also to reduce stress from the other female swordtails. It is also important to have only few males to avoid them from fighting off the other fish in the tank. Always remember to never overstock the tank because this will only increase the stress of the fish.


When pregnant, the female shows a swollen belly and dark gravid spot. It will not be hard to identify and know that a female is close to giving birth because its belly will be much larger than usual, causing the female to struggle in moving around the aquarium. One the days leading up to birth, the female swordtails becomes inactive, may not eat, and very territorial. After birth, make sure to separate the mother from the breeding tank to ensure the survival of the young fry.

Swordtail Feeding and Diet

Swordtails are omnivores in the wild. They will feed on plants, insects, and invertebrates. This diet should be regularized and maintained by aquarists by feeding a variety of processed and natural foods. Frozen or live foods, blanched vegetables, and flake or granular food all belong in a diversified diet. They should be thoroughly checked for the safety and health of the fish. Some of them should even undergo a process like how vegetables like cucumber medallions, zucchini medallions, broccoli, and shelled peas, should be lightly blanched in boiling water. This is to make sure that they will sink in the aquarium before feeding them to the Swordtails.