Are Fruit Flies Good for Fish?

Fruit flies make a great food for many aquarium fish. All fish have adapted to specific diets, and many aquarium species eat small insects much like fruit flies in the wild. You can easily feed fish fruit flies in home aquariums.

  1. Benefits of Fruit Flies

    • Many aquarium fish are micropredators in the wild. This means they eat small invertebrates, like tiny crustaceans and insects. Fruit flies mimic the kinds of foods these fish eat in the wild. Many surface-dwelling aquarium fish like freshwater butterfly fish and river hatchetfish mostly eat tiny insects in the wild and thrive on such foods. In some species, feeding live foods like fruit flies may trigger spawning.

    Varities

    • Thousands of species of fruit flies exist in the wild. Generally only a handful show up in the aquarium trade. Within these species, several mutations make life easier for the aquarium hobbyist. Several kinds of fruit flies have little to no ability to fly, making them easier to feed to fish. They may have tiny wings or none at all. Flies with miniature wings can fly somewhat, but have smaller wings than wildtype flies. Vestigial-winged flies have stunted, twisted wings that can't fly.

    Culturing

    • Pet shops and Internet storefronts sometimes sell vials of fruit flies. However, you can also culture them at home yourself in gallon jars. To do this, mix fruit fly medium, add a popsicle stick so the flies don't drown in their food and add a few flies. Within a few weeks you'll have plenty of fruit flies. Different recipes exist for fly medium, but most consist of potato flakes, yeast and fruit material. You will want to have multiple cultures going, since the medium tends to go bad in a few weeks.

    Feeding Fish Fruit Flies

    • It is easiest to feed wingless fruit flies to fish. Just tap the container so they aren't at the neck of the bottle, then gently dump a few into the aquarium. Most fish will eagerly gobble them up quickly. Avoid overfeeding, since even wingless flies may escape. If you have winged flies, try keeping them in a refrigerator for a few minutes prior to feeding, so they become sluggish and less likely to fly away.