All fish / Pomacentridae

Half-and-half Chromis

Chromis iomelas

Also known as half and half chromis, half & half chromis, black and white chromis, bicolor chromis, two-tone chromis, ハーフアンドハーフクロミス, 半黑光鳃鱼

A small damselfish with a dark brown to black front half and a sharply contrasting white rear half and tail. It feeds on plankton in open water above outer reef slopes and is kept for its bold two-tone look, hardiness and reef safety.

Care at a glance

Care level

Easy

Temperament

Semi

Adult size

5.5 cm

Temperature

24 to 28 °C

pH

8.1 to 8.4

Smallest tank

120 litres

Keep as

Small group of 5 or more in a larger tank, or singly

Diet

Omnivore: zooplankton substitutes such as mysis, brine shrimp, copepods, quality flakes and pellets fed several times a day

Swims

Middle of the tank

Lifespan

5 to 8 years

Water

Marine (saltwater)

Wild range

Western and central Pacific: Coral Sea, Great Barrier Reef, New Caledonia, Fiji, Samoa to French Polynesia

Breeding

Males clear a nest site on rock where females lay sticky eggs, which the male guards until they hatch after a few days. Spawning happens in aquariums but rearing the tiny pelagic larvae is difficult and rarely achieved at home.

Good to know

More territorial than the green chromis and can bully its own kind in small tanks, so give plenty of rockwork or keep one. Wild caught; do not confuse with the similar Chromis dimidiata from the Indian Ocean.