All fish / Pomacentridae

King Demoiselle

Chrysiptera rex

Also known as king damselfish, king damsel, regal demoiselle, rex damsel, ヒレナガスズメダイ, 雷克斯豆娘鱼

A small damselfish with a blue to purplish head and upper body that fades into a yellow or peach belly and tail, often with a dark spot behind the eye. It lives on shallow, surge-swept reef flats and is kept because it is hardy, colourful and coral safe.

Care at a glance

Care level

Easy

Temperament

Semi

Adult size

7 cm

Temperature

24 to 28 °C

pH

8.1 to 8.4

Smallest tank

110 litres

Keep as

Singly, or as a pair in a larger tank

Diet

Omnivore: marine flakes and pellets, mysis, brine shrimp, finely chopped seafood and some algae

Swims

Middle of the tank

Lifespan

5 to 10 years

Water

Marine (saltwater)

Wild range

Western Pacific: Indonesia, Philippines, Taiwan, southern Japan, Great Barrier Reef and nearby islands

Breeding

Pairs lay sticky eggs on a cleaned hard surface, and the male guards them until they hatch. Spawning can happen in captivity, but rearing the tiny pelagic larvae is difficult and rarely achieved at home.

Good to know

Like most damselfish it becomes territorial with age and may bully smaller or similar-looking fish, so add it last and give plenty of rockwork. Keeping several together in a small tank usually leads to fighting.