Praecox Rainbowfish (Melanotaenia praecox)

Melanotaenia praecox, the dwarf neon rainbowfish, runs a genuinely saturated blue-and-red combination that rivals anything in the tetra world, packed onto one of the smaller-bodied species in the Melanotaeniidae family, which makes it accessible for tanks that couldn't fit a full-size Boesemani or New Guinea rainbow. It's also one of the more popular rainbowfish species specifically because that color shows up faster and more reliably than in some of its slower-coloring relatives. A great centerpiece school under good lighting.

Care level: Easy · Temperament: Peaceful, shoaling · Max size: ~3" · Min tank: 20 gal · Diet: Omnivore, flake/pellet