Fire dartfish

Description

The fire dartfish is a small marine fish of the family Microdesmidae, usually no more than 8–9 cm long. Its slender body is pearly white at the front, shading into an ever more intense orange and red towards the tail. Its most distinctive feature is the first dorsal fin, drawn out and thin like a plume, which the fish holds erect and flicks constantly, almost like a little flag.

Habitat and distribution

It lives on the coral reefs of the Indo-Pacific, from East Africa to the Pacific islands, from the surface down to several tens of metres. It prefers the outer reef, where it hovers in the water just above the bottom, ready to dart into a burrow at the slightest threat.

Behaviour

It is a shy, peaceful fish that spends its time hovering against the current to catch the zooplankton it feeds on. At the least alarm it shoots into a crevice. It lives alone or in pairs and firmly defends its shelter from other fire dartfish.

In the aquarium

It is one of the best-loved reef fish in marine aquariums, being hardy, small and suited to living alongside corals and invertebrates. It must be kept in a well-covered tank, because when startled it tends to jump out of the water. It is best kept alone or as a settled pair, with plenty of hiding places and calm tank-mates.

Did you know?

Its many common names — fire dartfish, fire goby, magnificent fire fish — all come from the blazing colours of its tail and its darting movement, which recalls a tongue of flame.