Tropical reef fish
Identity card
Red Sea and Indo-Pacific.
Between 1 and 20 metres deep.
10 cm max., 5 to 8 cm.
Plankton.
3 to 4 years.
The damselfish hides inside a coral reef at night to sleep.
When asleep, fish move their fins twice as much as when awake. These movements improve hydrodynamics and maintain the level of oxygen in the water necessary for the internal parts of branching coral reefs.
This is a mutualistic relationship between the fish and the coral, which serves as a refuge for the fish.
The damselfish live in shoals, close to the corals where they can take shelter at the slightest sign of danger.
This species inhabits hard substrates in lagoons and subtidal reef flats. They are often found in groups among Acropora and Pocillopora branching corals.
It is found in the Red Sea, throughout the Indian Ocean and in the Pacific from Australia to the Tuamotu Archipelago, and from southern Japan to New Caledonia and the Tonga Islands.
Its almond-shaped body is turquoise blue to green in colour with a forked caudal fin resembling a swallow's tail. It is therefore known as the blue damselfish, green damselfish or blue-green chromis.
The male is larger than the female.
The males prepare the nest for egg laying, which is shared with several females. A large number of eggs are laid and hatch within 2 to 3 days.
The males guard the nest by fanning the fertilised eggs laid on the substrate or algae with their caudal fins and feeding on those that do not hatch.
The damselfish is born female and can change sex as it grows to become male.
There are no specific conservation measures for this species.
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