Galactic Purple GLO Shark (Epalzeorhynchos frenatum)

GLO fish carry a marker gene borrowed from a naturally fluorescent marine organism, inserted early enough in development that it shows up in every cell — the same basic trick used to make GLO tetras and GLO corys glow pink or orange, just applied here to a rainbow shark base. Strip away the electric-purple glow under blue light and it's the same territorial, cave-claiming cyprinid underneath, one best kept solo. Multiples can work, but only in a tank large enough that each fish can stake out its own cave well out of sight of the others — undersize the tank and that territorial streak turns into a permanent border dispute.

Care level: Easy · Temperament: Semi-aggressive, territorial · Max size: ~6" · Min tank: 30 gal (add tank size for each additional fish kept together) · Diet: Omnivore, sinking pellets/veggies