Photo by Mika d’Eau
One of the most beautiful fish from our reefs, the Harlequin Filefish, Orange Spotted Filefish or Longnose Filefish (Oxymonacanthus longirostris) can be usually found near its food source, Acropora coral. Most often, they are found in pairs swimming in synchronized motion and only grow to a very maximum of 10cm/4in. Although they are not a daily sight in the Maldivian waters our guides will know where to find them!
Filefish, also known as leatherjackets in some parts of the world are closely related to Triggerfish and Pufferfish. Filefish are in the family Monacanthidae meaning one spine. Similar to Triggerfish, they have a prominent first dorsal spine which can be raised for defense or wedging themselves into a hole. Filefish obtain their name from their rough non-overlapping scales which have small spikes on them which gives their skin a very rough texture.
They are always found near their food source, the Acropora corals They are fairly shy during the day and unless they are hiding in the branches of Acropora coral are difficult to approach. They are very quick to hide in the branches of the Acropora corals. At night the fish will anchor inside Acropora branches to camouflage itself from predators. They even have the ability to at least darken the lower section of the body, presumably for camouflage purposes. It appears that the chemicals the filefish absorbs from the Acropora coral camouflages it chemically, giving predators the chemical impression that it is just a piece of Acropora coral. This is apparently the first evidence of such behavior in a vertebrate.
In the Maldives, they are mainly found in the first 8m/24ft to 10m/30ft because this is were the Acropora are to be found. Their diet is highly specialized. They use their long snout to nip off the coral buds only one species of corals: Acropora millepora corals. They simply bite off the polyp without biting the skeletal cup. Unfortunately, research has shown that if their food resource dies, they will rather starve to death than switch diet.
Spawning takes place in prepared areas on a substrate and the eggs are guarded by the parents. Once the eggs hatch the juveniles are initially pelagic.
Photo by Mika d’Eau
