Do Baby Swordtails Hide in Gravel?

Swordtails are common in the aquarium trade. They belong to the guppy family, and they breed frequently in the home aquarium. If you want to raise the young, you need to find a way to protect them from their parents to ensure they grow beyond bite-size.

  1. Swordtail Breeding

    • Swordtails readily breed in home aquariums. Females can produce multiple batches of offspring from a single mating; males try to mate constantly, unlike many fish, who breed only once a year. As such, female swordtails are almost permanently pregnant and give birth every month or so. However, adult swordtails are enthusiastically cannibalistic towards their young, so it's rare for more than a handful to make it to adulthood unless you go out of your way to see to it that the fry are protected from their parents.

    Hiding Places

    • One strategy for raising swordtail fry to adulthood is providing hiding places. Swordtail fry may hide among the aquarium gravel, but this does not provide adequate cover to hide them from hungry adults. A densely planted aquarium works better. Bushy artificial plants work well, since they require much less care than live plants. Additionally, many pet shops sell "baby grass," plastic aquarium plants specifically designed to keep baby fish safe from adults.

    Breeding Aquariums

    • You can raise more swordtail fry to adulthood by moving pregnant females to a separate breeding aquarium when they get ready to give birth. This allows you to raise the fry away from predatory parents and tend to them more closely. When a female swordtail gets ready to give birth, you will notice a swelling of the gravid spot, a silvery-black spot at the back of a female swordtail's abdomen. With a little practice, you will be able to tell when a female swordtail's gravid spot has reached the point that birth is imminent. At this point, scoop the swordtail in a cup -- not a net -- and move her to the breeding tank until she gives birth. Unlike mammals, swordtails do not provide much nutrition to their young prior to birth, so you can safely put her back in the main tank as soon as she finishes giving birth without any kind of recovery time.

    Caring for Fry

    • Swordtail fry may have trouble with adult-size food. However, unlike many fish fry, swordtail fry do not need much in the way of special food. You can feed swordtail fry ground-up fish flakes until they are old enough to eat regular flake food. You can promote growth with the occasional live food treats like baby brine shrimp and daphnia. Feed two to three times a day.