Rainbowfish and blue-eyes
Australasian atheriniforms whose males colour up only in competition, and often only after a year or two. Most want hard alkaline water, which is the opposite of what their tankmates are usually given.
18 species, separated by adult size. Part of the freshwater fish catalogue.
Nano — under 4 cm (2)
Small enough for tanks under 60 cm, and usually needing larger groups than their size suggests.
Small — 4 to 8 cm (6)
The core of most community tanks.
- Dwarf neon rainbowfishMelanotaenia praecox7 cmUndemandinggroup of 6+
- Forktail blue-eyePseudomugil furcatus5 cmModerategroup of 8+
- Macculloch's rainbowfishMelanotaenia maccullochi7 cmUndemandinggroup of 6+
- Pacific blue-eyePseudomugil signifer5 cmUndemandinggroup of 8+
- Spotted blue-eyePseudomugil gertrudae4 cmModerategroup of 8+
- Threadfin rainbowfishIriatherina werneri5 cmDemandinggroup of 8+
Medium — 8 to 15 cm (8)
Needs real swimming length. Frequently sold as juveniles into tanks that will not suit the adult.
- Banded rainbowfishMelanotaenia trifasciata13 cmModerategroup of 6+
- Boeseman's rainbowfishMelanotaenia boesemani12 cmUndemandinggroup of 6+
- Celebes rainbowfishMarosatherina ladigesi8 cmModerategroup of 6+
- Crimson-spotted rainbowfishMelanotaenia duboulayi11 cmUndemandinggroup of 6+
- Eastern rainbowfishMelanotaenia splendida12 cmModerategroup of 6+
- Lake Kutubu rainbowfishMelanotaenia lacustris12 cmModerategroup of 6+
- Lake Tebera rainbowfishMelanotaenia herbertaxelrodi11 cmModerategroup of 6+
- Madagascar rainbowfishBedotia madagascariensis12 cmUndemandinggroup of 6+
Large — 15 cm and above (2)
Specialist tanks. Check the adult size and the lifespan before buying.