True Rainbowfish belong to the family Melanotaeniidae and are only found in Australia and New Guinea. The Madagascar and Celebes Rainbowfishes are related, but generally not considered true rainbowfish. There was a published report attempting to realign the rainbowfish families, but it did not gain acceptance in the scientific community. Shortly after publication a rebuttal was published contradicting the results of the earlier study. Here we will use the most generally accepted family classifications.
The Family Melanotaeniidae - Rainbowfish