nounplural noun rainbowfish, plural noun rainbowfishes
Any of a number of small brightly coloured fish of warm waters.
an Australian freshwater fish (genus Melanotaenia, family Melanotaenidae).
('Celebes rainbowfish') a freshwater fish native to Sulawesi and popular in aquaria (Telmatherina ladigesi, family Atherinidae).‘Visual cues alone allow for the expression of a preference for familiars in guppies and rainbowfish.’
- ‘Surface feeders such as rainbowfish will benefit greatly from feeding vinegar eels, but a lot of cichlid fry are bottom feeders.’