Black Triggerfish

Interesting Info

• The Black Triggerfish is found throughout the Indo-Pacific, including northern Australia — most commonly on the Great Barrier Reef, Coral Sea, and reefs of Western Australia.
• Despite the name “black,” their body can actually shine blue, green, or even purple in bright sunlight, with subtle lines running along the head and fins.
• They grow up to about 45–50 cm (1.5 ft) long, making them a medium-to-large triggerfish.
• Their body is streamlined and oval, built for speed and cruising in open water rather than hiding in the reef like some of their cousins.
• They are usually found in schools, sometimes mixing with surgeonfish or other planktivores, hovering above reef slopes and drop-offs.
• Their preferred depth range is from the surface down to about 75 m (246 ft), but divers often see them around mid-water at 10–30 m.
• They are mainly planktivores, feeding on zooplankton drifting in the current. They will also nibble on algae and small invertebrates if the opportunity arises.
• Unlike many other triggerfish, the Black Triggerfish is considered non-aggressive and rarely bothers divers, even during breeding.
• During spawning, they gather in large schools, with females releasing eggs into the water column and males fertilising them. The fertilised eggs drift with the currents until hatching.
• Juveniles often shelter among floating seaweed or debris, where their dark colouring makes them almost invisible to predators.
• They play an important ecological role as plankton feeders, helping transfer energy from open water plankton communities to the reef food web.
• They can live for 10 years in the wild.