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.
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.
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.
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.
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.
Arabian Picasso triggerfish
Our underwater life experts are here to help you identify a species you've seen. Please specify where you saw this species and, if possible, attach a photo
Want to learn more about the species you’ve observed or photographed underwater?
The identification guides are true treasures for those curious to know about the underwater world, and a beautiful way to dream about your future snorkeling explorations!
Get monthly updates on trending destinations, amazing snorkeling trips, useful snorkel gear tips, and so much more.