The boxfish family belongs to the order Tetraodontiformes. They are therefore closely related to the Pufferfish, Porcupinefish and Filefish. The family has seven genera and 25 species.


Boxfish have a distinctive angular appearance. Their body consists of hexagonal bony plates that form an internal armor. This gives the fish its distinctive pentagonal, square or triangular shape. The beak and caudal fin are located on the corners and openings in the armor.

The dorsal and anal fins are far back. The dorsal fin has only soft fin rays. The pelvic fins are completely absent. They mainly swim with their pectoral fins. The tail fin can give them some acceleration, but that is only for short stretches. The internal armor ensures that the fish does not make graceful movements with which other fish species slide through the water. The boxfish is really as rigid as a suitcase …. but with fins. The largest species (Acanthostracion quadricornis) can grow up to 60 centimeters in length.


You can find boxfish in the tropical waters of the oceans. They live in the Atlantic, Indian and Pacific Oceans.


With their small fins and rigid body, boxfish are not fast swimmers. They feed on algae, tunicates (Tunicata), Hydrozoa and sponges.


Some boxfish can secrete the poison ostracitoxin. In case of danger, they release this poison. An predator will therefore think twice before eating a boxfish.

This poison can also cause problems in the aquarium. It is therefore often not recommended to keep boxfish in the seawater aquarium. The problem not only arises when a boxfish is cornered, but also when it unexpectedly dies. At that moment, the fish also releases its poison. If you don’t catch it in time, this poison can poison a large part of your aquarium. Boxfish themselves are not always resistant to their own poison.

So pay close attention when catching and transporting these fish. When transporting, make sure you take them in plenty of water so they don’t poison themselves.

Boxfish breeding

Boxfish lay their eggs in open water (pelagic zone). The eggs are fertilized and temporarily become part of the plankton. So they are not bred in captivity.

Below you will find the boxfish species that we have included in the database:

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