Atlantic (grey) triggerfish

Balistes capriscus

IUCN Status:Vulnerable

Where can they be found?

Surprisingly common around the south and west, where the gulf stream provides the warmth they need to survive.

Please note: this map is intended as a guide for general locations rather than detailed localised populations.

Did you know... An interesting feeding behaviour has been observed where they position themselves vertically above a sandy seabed and puff streams of water from their mouths, disturbing the sand to reveal something edible. The prey can then be gripped with the fish's sharp teeth and eaten.

Key facts about Atlantic (grey) triggerfishs

A tropical-looking fish with scrawly grey markings, one of the Atlantic triggerfish’s most distinctive features is its beak-like mouth, formed by fused teeth that create a powerful bite. This allows the triggerfish to crack open the toughest shells of mussels, clams, and other hard-shelled prey with ease.

The fish gets its name from how it can lock its dorsal spine upright for defense. When threatened, the triggerfish wedges itself into a crevices and raises this spine, making it nearly impossible for predators to dislodge. A second spine acts as the release “trigger,” which lowers the first spine when danger has passed.

Although native to warmer regions, the Atlantic triggerfish is increasingly spotted in southern and western UK waters ever since the mid-2000s, and they are especially spotted during the summer months. Unfortunately, the increasing presence of Atlantic triggerfish in UK waters is widely considered a sign of rising ocean temperatures.

IUCN status Vulnerable
Age 8 years in the wild, but can live up to 20 years when looked after well in an aquarium.
Diet They feed on benthic invertebrates like molluscs and crustaceans.
Habitat Subtidal
Length 44cm
Speed and distance Atlantic triggerfish aren't great swimmers and use a swimming style called balistiform locomotion where they guide themselves using their fins. They can dart away quickly when necessary though but this is a sudden burst of speed rather than a maintained one. They are fairly lazy swimmers and use currents to drift around as juveniles such as the Gulf stream. However as adults they are usually stay in one area rather than travel.
Weight 2.3kg