Filefish are marine fishes belonging to the family Monacanthidae in the order Tetraodontiformes. This is a highly diverse family that contains over 100 species divided into over 25 different genera. The filefishes are known under many different names, including foolfish, shingles and leatherjackets. They are closely related to pufferfish, triggerfish and trunkfish.
Several species of filefish haven been successfully kept by marine aquarists, but it is important to keep in mind that certain species will eat corals and invertebrates.
In Korea, filefish is dried and turned into sweet and salty jerky, then roasted and sold as a snack.
It is said that dried filefish skin was once used to smooth boats made from wood and that the name filefish is derived from this usage. The skin of a filefish is very rugged and feels like sandpaper.
Habitat, habits and geographical range
Filefishes are found in tropical and subtropical parts of the Atlantic, Indian Ocean and Pacific Ocean.
Adult filefish will typically stay in the shallow parts of the sea and rarely venture further down than 30 meters (100 feet). They are known to appreciate lagoons, seagrass beds and coral reefs near the coast. Some species occur in estuaries. Young specimens are pelagic and inhabit open waters.
Their social habits vary from species to species. Some form pairs, some live in small groups and some prefer to stay alone.
The filefish looks like a squashed trunkfish with small fins and it comes as no surprise that this fish isn’t a very fast or agile swimmer. If it feels threatened it will typically retreat into a crevice or cave in the reef rather than trying to out-swim a predator. There are also species that spends most of their life hidden in dense mats of sargassum (a type of sea weed).
You can often see filefishes drifting with the current among seaweed with their head pointing downwards. This is probably a way of fooling both predators and suitable prey.
As mentioned above, the family Monacanthidae is a highly diverse family and this is true when it comes to feeding habits as well. Before you purchase filefish for your aquarium it is very important to find out the feeding requirements of that particular species. Some species are chiefly herbivore and feed primarily on algae and seagrass, while others are more omnivore and supplement the plants with plenty of small invertebrates. Hydrozoans, gorgonians and tunicates are just a few examples of aquatic creatures that frequently end up in the belly of a filefish. It is also important to remember that some species of filefish are corallivores, i.e. they eat corals and are not recommended for reef aquariums.
The reproductive habits vary a lot between the various species of filefish. Generally speaking, the male will prepare a nest at the bottom where the eggs will be deposited. The nest will then be guarded by the male alone or by both parents, depending on species.
Saddled Filefish – Paraluteres prionurus