Cosmic Blue GLO Tetra (Gymnocorymbus ternetzi)

Blue is the newest and trickiest color in the GloFish lineup to stabilize, since fluorescent proteins that read blue under aquarium light are harder to express cleanly than the red and orange spectrum genes that came first. The heritable gene traces back to the same zebrafish pollution-biosensor research behind every other GloFish color, just refined further to land here. Easy, peaceful, and a standout in a school of otherwise ordinary tetras.

Care level: Easy · Temperament: Peaceful, shoaling · Max size: ~1.5" · Min tank: 15 gal · Diet: Omnivore, flake/micro-pellet