Sunburst Orange GLO Corydoras (Corydoras paleatus)

This is the same fluorescent-gene technology behind every GLO fish — a marker gene from a naturally bioluminescent organism, inserted early in development so every cell, including reproductive ones, carries the trait — run through a hardy paleatus-line cory and finished in a vivid orange that pops under actinic or blacklight. Strip away the glow and you've still got a classic peppered cory: barbel-foraging, group-oriented, and about as beginner-proof as catfish get.

Care level: Easy · Temperament: Peaceful, shoaling · Max size: ~2.5" · Min tank: 20 gal · Diet: Omnivore, sinking pellets + occasional live/frozen