Emperor angelfish

The emperor angelfish is one of the most recognisable fish on an Indo-Pacific reef, a tall, disc-shaped fish that cruises slowly along a wall and slips into a cave when approached. It reaches about 40 cm and undergoes one of the most dramatic colour changes of any reef fish as it grows.

Also known as: pomacanthus imperator, angel fish, angelfish, emperor, imperial angelfish

Several reef angelfish begin life with a similar blue-and-white ringed juvenile pattern, which can cause confusion. Check the dorsal fin: this species is the one with a clean white margin along the top fin. Once it reaches the adult striped colouring, there is little else it could be mistaken for.

Juveniles are dark blue, ringed with curving lines of pale blue and white that wrap around the body and straighten into bars near the head; the tail fin is clear. As adults, the pattern changes completely: the body is blue with close-set horizontal yellow stripes, the face is light blue with a dark blue band over the eyes, and the tail is plain yellow. A blackish band, edged bright blue at the front and thin yellow at the back, runs above the pectoral fin, the fin just behind the gill cover.

This angelfish ranges right across the Indo-Pacific, from the Red Sea and East Africa to the central Pacific, north to southern Japan and south to the Great Barrier Reef; small numbers have also reached the eastern Mediterranean since 2009. It lives from 1 to 100 m. Adults favour clear lagoon, channel, and seaward reefs with rich coral growth, sheltering under ledges and in caves, while younger fish use holes on the reef front and in surge channels.

harmless

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  Angelfish

  angelfish

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  Bicolor angelfish

  Centropyge bicolor

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  Cortez Angelfish

  Pomacanthus zonipectus

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  French Angelfish

  Pomacanthus paru

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  Grey Angelfish

  Pomacanthus arcuatus

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  Keyhole Angelfish

  Centropyge tibicen