TankBud

Koran angelfish

Pomacanthus semicirculatus

Also known as Semicircle Angelfish, Blue Koran Angelfish

SaltwaterFish

Koran angelfish (Pomacanthus semicirculatus)
Stan Shebs · CC BY-SA 3.0

Care at a glance

Temperature
73–81°F
23–27°C
pH
8.1–8.4
Adult size
15.7 in
40 cm
Minimum tank
185 gal
700 L
Temperament
Mostly peaceful
Social behavior
Solitary
Own kind
One per tank
Tankmates
With caution
Swim level
Middle
Diet
Omnivore
Difficulty
Difficult
Breeding
Egg layer · Hard
Rarity
Common
Reef safe
Not reef safe
Family
Pomacanthidae
Origin
Indo-Pacific, from the Red Sea and East Africa to Samoa, north to southern Japan and south to Western Australia

Overview

The Koran angelfish is a large Indo-Pacific angelfish for a very big saltwater tank without corals. It is a fish for experienced keepers.

Did you know

The juvenile and adult Koran angelfish look so different that early collectors sometimes sold them as separate species.

Caring for the Koran angelfish

Give the Koran angelfish at least 185 gal (700 L), with mature, extensive rockwork and caves. The rock should carry established algae growth, so it can graze and hide much as it would in the wild.

Keep the water at 73 to 81°F (23 to 27°C) and a pH of 8.1 to 8.4. In the wild it grazes sponges, tunicates and algae. Offer nori and other marine algae alongside frozen meaty foods like mysis and brine shrimp.

The Koran angelfish is mostly peaceful, but it shows aggression toward other angelfish and similarly shaped fish. Keep only one per tank. It is not reef safe and will nip soft and stony coral polyps and clam mantles.

The Koran angelfish is hard to breed. A 2009 study documented its natural spawning, eggs and larvae in research aquariums. Few large angelfish have been recorded this way, so the study gave scientists a rare look at how a Pomacanthus angel breeds.

Good to know

Pomacanthus semicirculatus belongs to the family Pomacanthidae and also goes by semicircle angelfish and blue Koran angelfish. It can live two decades or more in good care. The juvenile is dark blue-black with concentric white and pale blue swirling rings, the semicircle pattern its scientific name refers to. The adult turns olive green to blue-gray, with fine scale markings and a pale blue mouth. Behind its gill cover sits a dark, comma-shaped mark ringed in blue.

In the wild

Koran angelfish range across a huge stretch of the Indo-Pacific, from the Red Sea and East Africa to Samoa. They also reach north to southern Japan and south to Western Australia. They live on reef flats, lagoons and outer slopes, from the surface down to about 40 meters. They stay close to shelter, ducking into rock and coral cover when startled.

Common questions

What size tank does a Koran angelfish need?

A Koran angelfish needs at least 185 gal (700 L). It spends most of its time in the middle.

What temperature and pH does a Koran angelfish need?

A Koran angelfish is comfortable at 73–81°F (23–27°C) with a pH of 8.1–8.4.

What does a Koran angelfish eat?

A Koran angelfish eats nori and other marine algae alongside frozen meaty foods like mysis and brine shrimp. In the wild it grazes sponges, tunicates and algae.

How big does a Koran angelfish get?

An adult Koran angelfish reaches about 15.7 in (40 cm).

How does a Koran angelfish breed?

Koran angelfish spawn naturally, producing eggs and then larvae, as a 2009 study in research aquariums recorded. Breeding them is hard.

Related species