Swordtails are perennial favorites in the aquarium. They are colorful active swimmers that are fun to watch. Both hardy and undemanding, swordtails have a distinctive ray that extends out from the caudal fin of the male. This elongated tail gives it its unique appearance and a healthy male specimen can be eye-catching in a well-planted tank. A native of Southern Mexico and Guatemala, the swordtail (Xiphophorus helleria) belongs to the family Poeciliidae, and is related to the molly, platy and guppy. It grows to a length of 4 inches (without the sword) and is a colorful and peaceful addition to a community aquarium.
Things You'll Need
- 10-gallon aquarium (minimum)
Prepare the aquarium by providing slightly hard, alkaline water between 70 degrees F to 79 degrees F. Swordtails are active, so a filtered, 10-gallon aquarium is the smallest size you should consider. A 25- to 30-gallon community tank would be ideal.
Provide lots of floating plants and vegetation. Swordtails like algae and can often be seen scraping algae from the sides of the aquarium. To insure a good supply of vegetation, make sure the tank receives a few hours of indirect light each day.
Supplement their vegetation by floating a washed, raw spinach or lettuce leaf in the aquarium occasionally. Remember to remove it after a few hours in the tank.
Select fish that are active and have erect, well-shaped fins. Fish that are sluggish or pale may be ill or have trouble adapting to a change of environment. The best candidates will be curious and lively.
Observe fish carefully for the first 72 hours after introducing them to the aquarium. They should be actively exploring their new environment within the first few hours, not hiding.
Allow fish to become acclimated before feeding them. When feeding new fish in the aquarium, less is more.
Feed swordtails dry flaked food, supplementing it with live food occasionally. Brine shrimp and mosquito larvae are welcome additions to their diet.
Tips & Warnings
- Swordtails can interbreed with platys.
- Swordtails can sometimes be bullies to fish much smaller than they are. To keep hostilities to a minimum, keep them with fish of roughly the same size, or keep them in large tanks where they are less likely to become territorial.
- Don’t confuse swordtails with mollies. Although mollies need the addition of salt to their water, swordtails do not.
- Swordtails are livebearers that can produce young every four to six weeks, with broods of up to 100 for older, larger females. Raising baby fish (fry) can be an interesting and educational experience, but it's easy to have a population explosion if you keep too many females.
About Baby Swordtail Fish
Next to the guppy, the most popular aquarium fish for breeders and hobbyists is the swordtail (Xiphophorus helleri). Baby swordtails, known as...