
General description
Rainbowfish are a family of small freshwater fish that get their name from their bright, iridescent colorations that change shades in different light settings. In recent times rainbowfish have started to gain popularity amongst aquarists for both their beauty and relatively hardy nature. They are also a relatively small species of aquarium fish with most species reaching only a couple of inches in length. In fact, the largest species of rainbowfish only reaches around 8 inches in length. Rainbowfish are an extremely peaceful species of fish and make excellent additions to community aquariums.
Rainbowfish are a family of small freshwater fish that get their name from their bright, iridescent colorations that change shades in different light settings.
Origins
Rainbowfish are native to northern and eastern Australia, New Guinea and certain regions of Southeast Asia.
Color
Rainbows come in a variety of colors ranging from red, blue, yellow, silver and black.
Maintenance and care

In their natural habitat rainbowfish inhibit rivers and streams with heavy plant growth. These conditions should be recreated in a heavily planted aquarium with several open spaces left for these highly energetic fish to swim freely. Rainbowfish are a schooling species and thrive when kept in large shoals of 10 fish or more. When kept in small groups or by themselves, rainbows can be very timid and tend to lose their bright colorations due to stress. The exact water conditions that the rainbowfish require vary according to the species and their natural habitats, but most species are relatively hardy and can adapt to a wide array of water conditions.
Rainbowfish are also extremely peaceful and make excellent tank mates for most small, non aggressive species of aquarium fish. They shouldn’t be kept with more aggressive and assertive tank mates that may harass them or out-compete them for food.
Feeding
Rainbowfish are omnivores and can be fed on a varied diet of flake based foods and live foods such as bloodworms, blackworms and glassworms.
Rainbowfish are a schooling species and thrive when kept in large shoals of 10 fish or more.
Breeding
While the individual breeding habits of different species may vary, rainbowfish as a family are usually prolific breeders. Given adequate nourishment and clean water conditions, they will often spawn quite readily in the aquarium. It is however recommended that spawning females be removed to heavily planted breeding tanks because of their tendency to eat their own eggs and fry on sight. The fry too are relatively slow growing and need to be fed on a diet of infusoria or vinegar eels until they are able to accept larger types of food.
Aquarium varieties
Bosemani Rainbow, Praecox Rainbow, Threadfin Rainbow, Eastern Rainbow, Celebes Rainbow, Turquoise Rainbow, Australian Rainbow, etc.
Photo credit: Eileen Kortright/Wikimedia; Thomas Gräfe/Wikimedia