Georgette Douwma / Emperor angelfish (Pomacanthus imperator) swimming past coral reef. Egypt, Red Sea.

Georgette Douwma / Emperor angelfish (Pomacanthus imperator) swimming past coral reef. Egypt, Red Sea.

Georgette Douwma / Coral reef scenery with an Emperor angelfish (Pomacanthus imperator) and soft corals. Egypt, Red Sea.

Georgette Douwma / Coral reef scenery with an Emperor angelfish (Pomacanthus imperator) and soft corals. Egypt, Red Sea.

Joel Sartore / Photo Ark / Emperor angelfish (Pomacanthus imperator) portrait, Sharjah Aquarium, UAE. Captive, occurs in Indian Ocean, Pacific Ocean and Red Sea.

Alex Mustard / Male Emperor angelfish (Pomacanthus imperator) swimming over garden of Fire corals (Millepora sp.) in morning sunshine, Ras Mohammed National Park, Sinai, Egypt, Red Sea.

Alex Mustard / Emperor angelfish (Pomacanthus imperator) swimming in front of Fire corals (Millepora dichotoma) and soft corals (Dendronephthya sp.) and (Scleronephthya sp) with Scalefin anthias (Pseudanthias squami...

Georgette Douwma / Emperor angelfish (Pomacanthus imperator) adult (left) and juvenile (right) composite image on black background, Andaman Sea, Thailand.

David Fleetham / Juvenile Emperor angelfish (Pomacanthus imperator), portrait, Yap, Micronesia, Pacific Ocean.

Magnus Lundgren / Emperor angelfish (Pomacanthus imperator) juvenile, Triton Bay, West Papua, Indonesia, Pacific Ocean.

Magnus Lundgren / Emperor angelfish (Pomacanthus imperator), portrait, Triton Bay, West Papua, Indonesia, Pacific Ocean.

Lewis Jefferies / Emperor angelfish (Pomacanthus imperator) feeding, South Ari Atoll, Maldives, Indian Ocean,