How to Keep Swordfish

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)
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Instructions

    • 1

      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.

    • 2

      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.

    • 3

      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.

    • 4

      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.

    • 5

      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.

    • 6

      Allow fish to become acclimated before feeding them. When feeding new fish in the aquarium, less is more.

    • 7

      Feed swordtails dry flaked food, supplementing it with live food occasionally. Brine shrimp and mosquito larvae are welcome additions to their diet.