Redtail Golden Shark (Epalzeorhynchos bicolor)

This is the same redtail black shark whose wild population has vanished from its native Thai river system, just carrying a xanthic gene that swaps the usual jet-black body for a warm gold while leaving that signature red tail untouched. Every fish of either color form sold today traces back to captive breeding programs, since there's no wild population left to collect from even if anyone wanted to. Multiples are possible, but only in a tank large enough for each fish to hold its own patch of real estate out of the others' line of sight — pack them into anything smaller and the territorial disputes never really stop.

Care level: Easy · Temperament: Semi-aggressive, territorial · Max size: ~6" · Min tank: 55 gal (add tank size for each additional fish kept together) · Diet: Omnivore, sinking pellets/veggies