Marine life identification guide > Triggerfish & filefish

Triggerfish & filefish species identification guide

We have chosen to present here two very close families, the Balistidae (triggerfish) and the Monacanthidae (filefish). Species of these two families have in common a compressed body, an erectile spine above their head, and a very characteristic diamond shape.

A unique diamond-shaped fish

Triggerfish and filefish are hard to confuse with other reef fish. Their massive diamond-shaped body is easy to identify, and their colorful geometric patterns make some of them emblematic in the tropical seas.

There are 40 triggerfish and more than 100 filefish species in the world. Some of them appreciate the shallow waters of the lagoons and are easy to see while snorkeling.

Reef triggerfish
The reef triggerfish is the state fish of Hawaii. It is easy to spot throughout the archipelago (here, in Napili Bay).

Triggerfish are named after the erectile dorsal fin that they draw when threatened, but they are generally inquisitive and don’t hesitate to come close to swimmers.

During mating season, triggerfish can get aggressive while keeping their nests and sometimes bite intruders, some of them being snorkelers. The titan triggerfish, which can reach 70cm long, is famous for its dreadful bites. Filefish are more peaceful.

Where do the different triggerfish species live?

The most famous triggerfish undoubtedly is the lagoon triggerfish (or Picasso triggerfish). It is widespread in tropical seas of the Indian and Pacific Oceans. It can notably be seen in lagoons, even in shallow areas. It looks like its white and yellow stripes have been hand-painted onto its faded black body.

One of its cousins, the reef triggerfish, has been chosen as a symbol to the Hawaii State, where it is locally known as “Humuhumunukunukuapua’a”. But it’s not endemic to the archipelago: the reef triggerfish occurs from the Eastern African Coasts to French Polynesia.

If we had to give an award to the most fanciful scales pattern, it would be to the clown triggerfish with its white circles in contrast to a black body and its bright yellow lips.

Orangespotted filefish
The harlequin filefish, generally seen in pairs, is one of the most colorful members of the family. Here, encountered in Lagon de Saint-Pierre, Réunion.

The Arabian Picasso triggerfish, with its fluorescent-blue rimmed eyes, can exclusively be seen in the Red Sea and only 6 triggerfish species live in the Caribbean Sea.

The most common filefish is the scrawled filefish, with a circumtropical distribution. In the Caribbean, two species are particularly easy to see: the whitespotted filefish and the orangespotted filefish.

The prettiest filefish may be the harlequin filefish, adorned with a superb turquoise and golden robe, which occurs from East Africa to Melanesia.

Caribbean & Western Atlantic triggerfish and filefish



Indian & Pacific Oceans triggerfish and filefish



Eastern Pacific Ocean triggerfish


Mediterranean and Eastern Atlantic Ocean triggerfish and filefish

Triggerfish and Filefish

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