The Emperor Angelfish (Pomacanthus imperator), called Imperator for short, is a species of the genus Pomacanthus in the family Pomacanthidae. They grow 40 centimeters long and live up to 14 years. Its range is the Indo-Pacific: it is found from the Red Sea to Hawaii. Its habitat is coral reefs in water depths up to about 25-50 meters. These fish usually live in pairs in caves and aggressively defend their large territories. If they feel threatened, they may emit grunting sounds.
Imperator angelfish undergo a fascinating color change during their life:

Juvenile
Age a few months
Size about 5 cm long
As juveniles they are dark blue colored with concentric white and light blue rings, the center of which is just before the root of the tail.
This fish currently lives on the house reef in
Sahl Hasheesh.

Beginning color change
Length about 15 cm
Note the circle with the dash at the caudal fin and
the beginning color change over the back.
Very rare to see something like this, let alone photograph it.
Johann was lucky in 2013 in El Quseir.

Adult emperor
Up to 40 cm in length.
Age up to 14 years
A alternating yellow and blue, horizontal stripes on the body flanks, across the eyes extends a broad, jet-black eye band, fringed with bluish.
Can be observed on many reefs.

Author & Photos: Johann Vifian

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