Mandarin Dragonet

Fascinating facts about the Mandarin Dragonet

• The mandarin dragonet is one of only two animals known to have true blue colour produced by pigment cells. In almost every other blue animal the colour is a structural trick of light, but the mandarinfish carries actual blue pigment (cyanophores) in its skin — a distinction it shares only with its close relative, the psychedelic mandarin.
• It has no scales. Instead its body is wrapped in a thick, foul-tasting mucus studded with toxins that deter predators and ward off parasites and infection — the smell is so distinctive the fish is sometimes called the “stinky” dragonet.
• Barely 6 centimetres long, it is a slow, deliberate hoverer rather than a swimmer, sculling just above the rubble and coral of sheltered Pacific reefs on fan-like pectoral fins as it hunts tiny crustaceans.
• Its mating is one of the reef's great spectacles. At dusk, a male and female press together and rise slowly off the bottom in a vertical “dance”, releasing a cloud of eggs and sperm at the top of the ascent before darting back down — a ritual divers travel the world to witness.
• Males are larger and flash an extra-long, pointed first dorsal-fin spine; they compete fiercely for females, and a successful male may spawn with several partners in a single evening before the reef goes dark.

At a glance

About the Mandarin Dragonet

The Mandarin Dragonet (Synchiropus splendidus), often called the mandarinfish, is among the most extraordinarily coloured animals in the sea — a palette of electric blue, orange and green swirled into psychedelic, maze-like patterns across its tiny body. Native to the warm inshore reefs of the western Pacific, from Japan's Ryukyu Islands south to Australia, it lives a secretive life among coral rubble and the branches of sheltered lagoons, rarely straying into open water. A member of the dragonet family, it moves with a slow, almost insect-like hover, propelled by constantly fanning pectoral fins as it picks tiny crustaceans from the reef. Despite its dazzling appearance it is shy and easily overlooked, emerging most visibly at dusk for its remarkable courtship — and its beauty has made it one of the most coveted, and most difficult to keep, fish in the marine aquarium trade.

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