Alex Mustard / Emperor angelfish (Pomacanthus imperator) with Cleaner shrimp (Urocaridella sp.) grooming it. South Ari Atoll, Maldives. Indian Ocean.

Georgette Douwma / Emperor angelfish (Pomacanthus imperator) swimming past soft corals (Dendronephthya sp]), Red Sea, Egypt. January.

Alex Mustard / Emperor angelfish (Pomacanthus imperator) close up pattern detail, Ras Umm Sid, Sinai, Egypt. Red Sea.

Georgette Douwma / Emperor angelfish (Pomacanthus imperator) swimming past Soft corals (Dendronephthya sp) and Lyretail anthias (Pseudanthius squamipinnis). Egypt, Red Sea. Indo-Pacific.

Pascal Kobeh / Bruun's cleaner shrimps (Urocaridella antonbrunii) cleaning Emperor angelfish (Pomacanthus imperator) Maldives. Indian Ocean.

Alex Mustard / Close up of pattern of adult Emperor angelfish (Pomacanthus imperator) Tulamben, Bali, Indonesia. Java Sea.

Alex Mustard / Detail of pattern of an adult Emperor angelfish (Pomacanthus imperator) Seraya, Tulamben, Bali, Indonesia. Java Sea.

Georgette Douwma / Lyretail anthias / Goldies (Pseudanthias squamipinnis) on reef top. Egypt, Red Sea.

Georgette Douwma / Emperor angelfish (Pomacanthus imperator) swimming past soft corals (Dendronephthya sp) Egypt, Red Sea.

Georgette Douwma / Emperor angelfish (Pomacanthus imperator) feeding on soft coral. Egypt, Red Sea.

Georgette Douwma / Emperor angelfish (Pomacanthus imperator) feeding on soft coral. Egypt, Red Sea.

Georgette Douwma / Emperor angelfish (Pomacanthus imperator) at a cleaning station amongst soft corals, where small cleaner shrimps operate. Egypt, Red Sea.