Grey Triggerfish
Balistes capriscus
The Grey Triggerfish is a fish with a distinctive appearance belonging to the family Balistidae. The body is high and oval, very compressed at the sides, and covered by extremely tough skin that resembles armour. The colour is usually grey or olive with various shades that allow the fish to hide effectively. Its most striking feature is the trigger mechanism in the first dorsal fin. The first spine is very strong, and when it is raised, it locks into place by a second, smaller spine. This allows the fish to wedge itself into rock crevices, making it impossible to pull out. The mouth is small but features very powerful teeth that look like a beak.
Habitat
This species lives near the seabed, usually in rocky areas, reefs, and Posidonia seagrass meadows. It is also frequently found under large floating objects or near shipwrecks. It moves from the surface down to 100 metres, though it prefers shallow waters between 10 and 50 metres.
Diet
The fish is a carnivore and very voracious. It uses its strong teeth to break the shells of its prey. It feeds primarily on organisms with hard shells, such as sea urchins, crabs, and shrimp, as well as various molluscs. It does not hesitate to attack smaller fish or steal bait from the hooks of anglers.
Reproduction
Breeding occurs in the summer, usually from July to September, when the waters are warm. The fish exhibits a specific behaviour because it builds a nest. The female digs a pit in the sand where she lays her eggs. It is impressive that the male or even both parents guard the nest with great aggression until the eggs hatch, while they chase away any intruder, including divers.
Fisheries
It is caught with nets, longlines, and handlines, but it is often considered a nuisance by fishermen because it cuts fishing lines with its teeth. It has a relatively low commercial value mainly because cleaning the fish is difficult, as the skin is so tough that a specific technique is required to remove it. Despite this, the flesh is white, firm, and extremely delicious, and it reminds people of the taste of chicken or crab.
Research
The International Union for Conservation of Nature classifies the Grey Triggerfish as Vulnerable on a global scale because populations have decreased significantly in many areas due to overfishing. In the Mediterranean, the situation is somewhat better, but it remains a species under monitoring. Research has shown that the increase in water temperature due to climate change favours its expansion into northern regions. Furthermore, studies on its behaviour confirmed its high intelligence and its ability to learn and adapt to new conditions.