The rainbowfish is primarily a surface feeder and food that stays near the surface is therefore best. Do not give large portions, since uneaten food will sink to the bottom and be left there to pollute the water. Several small portions spread out over the day is much better. (If you have trouble keeping the water quality up in your aquarium, combine your rainbow fish with bottom dwelling scavengers like Corydoras catfish.)
It is not hard to get rainbowfish to eat in captivity and they will normally accept all sorts of food. The rainbowfish is an omnivore species that eat both animals and vegetable material in the wild. You can for instance use a high-quality flake food for herbivores or omnivores as a base and supplement with meaty food, e.g. mosquito larvae, brine shrimp, daphnia and cut up fish fillets and earthworms. Live food is better than dry and frozen foods, especially if you want to breed rainbowfish. Fresh vegetables are also appreciated. In the wild, rainbowfish feed primarily on insects, insect larvae, small crustaceans, zooplankton, phytoplankton and detrius. They eat both aquatic animals and terrestrial creatures that are unfortunate enough to fall into the water.
Many sellers of prepared foods claim that their product will provide your fish with everything they need and render all other food types unnecessary, but listening to such claims can be dangerous. In the wild, rainbow fish feast on a long row of different animals and they will also ingest algae and plant matter. It is impossible for a producer of prepared foods to know exactly what a rainbowfish needs and in which quantities and cram all that into a flake. It is therefore always safest to provide your rainbow fish with a variety of food. When stomach content of wild rainbowfish has been examined it has contained a long row of different things, including seemingly odd stuff like pollen and seeds.
Food is not only a way for the fish to ingest nutrients; it will also provide the fish with something to do in the aquarium. In the wild, rainbow fish are always on the lookout for tasty morsels. If you feed your rainbowfish live food now and then, they will be able to engage in their natural predatory behaviour.
Since the rainbowfish is such a happy eater in the aquarium, it is easy to over feed it. Over feeding is just as dangerous as malnutrition and must therefore be avoided. Over feeding can not only lead to digestive problems, lipodosis and obesity; it will also increase the risk of poor water quality in the aquarium. In the wild, rainbowfish are often found in environments where they are exposed to seasonal famines. They are therefore inclined to eat everything they can find since they always need to fatten up before the next dry season. In an aquarium without any dry seasons, it is up to the aquarist to provide the fish with proper amount of food and make sure that the fish is neither under-fed nor over-fed.
Australian Rainbow fish - Breeding and raising the Australian Rainbow fish, Pseudomugil gertrudae and Pseudomugil signifer.
Rainbowfish - An introduction to Rainbowfish
Rainbowfish Aquarium - Information about ho to setup an aquarium for rainbowfish.
Rainbowfish breeding and spawning - Learn how to breed these fish.
Rainbowfish Diseases - Information on different diseases that commonly infect these fish.
Keeping Rainbow fish - Information about how to keep rainbow fish and avoid some common problems.
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