Emperor Angelfish

About

The emperor angelfish (Pomacanthus imperator) is one of those fish that stops people in their tracks at the aquarium store. Adults wear bold horizontal yellow and blue stripes across the body, a dark mask over the face, and a bright yellow tail. But juveniles look like an entirely different species, dressed in deep blue with concentric white and electric-blue rings. That transformation as the fish matures is something hobbyists still find genuinely fascinating to watch. In the wild, this species ranges across a huge swath of the Indo-Pacific, from the Red Sea and East Africa all the way out to the central Pacific. Juveniles tuck themselves into reef ledges and protected lagoon areas, while larger adults move to caves and ledge systems in areas of rich coral growth. They feed heavily on sponges, tunicates, and other encrusting organisms. A diet that can be tricky to replicate in captivity and is one reason this fish is considered intermediate rather than beginner territory. They are also known to act as cleaners, picking parasites off much larger fish in the wild. In the aquarium, expect territorial behavior, especially toward other angels. This fish genuinely needs space. A serious, well-established reef or FOWLR setup with plenty of structure is the right home for one.