Rainbows are becoming more popular and widespread in the aquarium hobby because of their unique coloration, low maintenance and easy breeding. Rainbowfish originated in the warmer climates of northern Australia and Papua New Guinea. Each species is unique and can even have micro variations within the species depending on which stream or lake they are caught.
They are an excellent community fish and most species school with their own species and even other Rainbowfish. Rainbowfish coexist with their own species and other community species such as Tetras and Discus. If breeding Rainbowfish it is important to be aware that they can and will crossbreed with other species. The resulting young are often discolored and stunted. If breeding Rainbows is on the agenda it is important to house them in a species specific aquarium.
Rainbowfish are a popular choice in the aquarium hobby due to their range of sizes. Some Rainbows will stay very small, such as Threadfin Rainbowfish. The Threadfin Rainbowfish grows to a maximum of 1" and has beautiful long fins and mirrored scales. Most dwarf Rainbow varieties will grow to a maximum of 1.5" (4-5cm) and look great as a large school in a big aquarium. They are an excellent substitute for some of the more common Tetra varieties like the Neon Tetra or the Cardinal Tetra.
Other Rainbows will grow to be very large in size, around 5-6" (10-15cm) in length. The Salmon Red Rainbowfish is a prime example of this. Males can reach 6" in length and adult varieties have a brilliant red shine. Larger Rainbowfish also have a lengthy lifespan of up to 10 years.