Koran Angelfish

The Koran Angelfish is found in the Indo-Pacific. Its geographical range stretches from East Africa and the Red Sea to Samoa. The range proceeds northwards up to southern Japan and southwards down to Western Australia and New South Wales, including Lord Howe Island.

This is a reef-associated species with a depth range of 1-30 meters / 3-100 feet. Juvenile specimens are typically found in shallow protected environments, while the adult fish seek out coastal reefs with prolific coral growth and plenty of hiding spots. It lives singly or in pairs.
Size and appearance

The largest scientifically measured Koran Angelfish was 40.0 cm / 15.7 in.

The juvenile fish has a bluish-black body decorated with concentric semi-circles. The change into adult colouration will typically occur over the size range 8-16 cm / 3-6 in.

The adult fish is brownish on the anterior and posterior third of the body, while the middle part of the body is greenish or yellowish. The sides are adorned with an abundance of spots, and the dorsal and anal fins have filaments with bright yellow tips. The head is yellow-green with sapphire-blue gill margins and eye rings. 

The source of the common names Semicircle Angelfish, Half-circle Angelfish and Half-circled Angelfish becomes clear when you look at specimens with a length of roughly 1-3 in / 2.5-7.5 in. During this stage, the body of the fish is adorned with irregular rear semicircles. As the fish grows bigger, the semicircles will develop into sweeping lines.


When the fish is roughly 4-7 in /10-18, it will display a blue pattern similar to Arabic scrip on the tail fin and that is why one of the common names for this species is Koran Angelfish. The pattern consists of blue markings against black between blue lines.