Depth
Balistes · Bony Fish

Grey Triggerfish

Balistes capriscus

0-40m
Depth Range
Variable
Max Size
Mediterranean
Distribution
0-40m
Depth Range
Variable
Max Size
Reef & Open
Habitat
Carnivore
Diet
Solitary
Social
LC
IUCN Status
Moderate
Sighting Likelihood
Kingdom Animalia
Phylum Chordata
Class Actinopterygii
Genus Balistes
Species capriscus

Bony Fish

Identification & Biology

  • IdentificationDeep, rhombus-shaped body heavily compressed laterally. Grey to olive-brown body with faint blue lines and spots. A strong first dorsal spine can be locked in an upright position. Small mouth with powerful, chisel-like teeth.
  • SizeUp to 60 cm total length, commonly 25 to 40 cm.
  • Social HabitUsually solitary or in pairs. Can be curious and bold around divers. Males guard nests aggressively.
  • HabitatRocky reefs, wrecks, and areas with mixed substrate. Often near vertical walls and drop-offs.
  • Depth1 to 100 m, most common between 5 and 50 m.
  • Feeds OnSea urchins, crabs, molluscs, and other hard-shelled invertebrates crushed with its powerful teeth.
  • DistributionEastern Atlantic from the British Isles to West Africa, including the Mediterranean Sea.
  • DescriptionA distinctive, boldly shaped fish that can wedge itself into crevices by locking its dorsal spine upright. Grey triggerfish are intelligent, curious, and occasionally aggressive, particularly when guarding nests. Their powerful jaws can crack open sea urchins and thick-shelled molluscs with ease. Increasingly common in the Mediterranean as waters warm.

Range

Habitat & Distribution

Found across the Mediterranean, inhabiting reef & open environments. Active from the surface down to 40m depth.

Where Malta divers have spotted this species

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Sightings are logged by divers using our What Did You See? dive-log tool. View the full live sightings map.

Detail

Preferred Environment

Reef & Open habitats, typically at depths of 0-40m. Most commonly encountered by divers at the shallower end of its range.

Encounter Tips

Best approached slowly and calmly. Avoid casting shadows directly over the animal. Neutral buoyancy and patience increase encounter success significantly.

Grey Triggerfish species card

Biology

Behaviour & Diet

Feeding Strategy

Feeds on sea urchins, molluscs, crabs and barnacles, using its strong beak-like teeth to crack open hard shells. Also takes algae and small fish.

Shell crusher

Reproduction

Nests in sandy depressions on the seabed. Both parents aggressively guard the nest, with the female fanning eggs to keep them oxygenated.

Nest guarder

Behaviour & Defence

Erects its first dorsal spine and locks it in place with a smaller trigger spine, wedging itself into rock crevices so tightly that predators cannot extract it.

Spine locking

Dive with diveshack

Where to Encounter in Malta

The following dive sites offer strong habitat match for Balistes capriscus. All are accessible on a guided dive with diveshack.

5-30m
North Malta

Cirkewwa

Rocky reef with caves, arches and ledges hosting a rich diversity of reef species.

View dive site ›
5-50m
Gozo

Blue Hole

One of the Med's most famous reef dive sites. Rocky walls and archways covered in life.

View dive site ›
18-36m
South Malta

Um El Faroud

The wreck lies on a sandy bottom surrounded by rocky reef -- a diverse habitat attracting reef species.

View dive site ›
IUCN Red List Least Concern

Conservation Status

This species is assessed as Least Concern on the IUCN Red List. Mediterranean populations face ongoing pressure from fishing activity, habitat degradation, and climate-driven changes to prey availability.

Source: iNaturalist Guide #888
by Lesley Clements (CC BY-SA)
diveshack Mediterranean Marine Life guide