The Titan Triggerfish, also known as a giant or moustache triggerfish, is a large species of triggerfish that are commonly found in the reefs and lagoons of the Indo-Pacfic, although it is absent in Hawaii. It is 75cm (30 in.) long, it is the largest triggerfish in its range. Only the stone triggerfish which is found in the east Pacific Ocean is larger. Their eyes also roll independently of each other, and are heavily armoured.
As mentioned above, they are commonly found in reefs and lagoons are basically reef workers, and are usually surrounded by other fish that are feeding from the leftovers. They eat coral, crustaceans, urchins, and shellfish. Their can be commonly found being busy on the job, turning over rocks, stirring up sand, and biting pieces off of branching coral. This is why people are able to see smaller fish species around it who are feeding from the leftovers.
The Titan Triggerfish is usually wary of snorkelers and divers, except during the reproduction season. During this season, the female titan triggerfish guards its nest which is placed on a flat, sandy area and vigorously guards it against any intruders. Although the bites are not 100% venomous, they can be aggressive and do have rather strong teeth which can inflict some serious injuries which may require some medical attention. However, their bites can cause infection as they contain Ciguatoxin, which is a natural poison. Ciguatoxin can have serious effects on human beings, where the most extreme cases cause heart attacks and even paralysis.
Some stories from people include having bodily parts bitten, or having holes in their flippers. If you are diving or snorkelling, and see a Titan Triggerfish, you will need to know its threat posture just in case it is reproduction season or you are wandering into their territory. They are extremely territorial, particularly doing April and May. During these breeding months, the male titan triggerfish will guard the nest and create a ‘protection zone’ which comes directly up from the nest in a conical shape as they can see upwards. When threatened, the Titan Triggerfish will face the intruder, while holding its first dorsal spine erect. It may also roll onto its side in order to see the intruder properly in case it sees it threatening its nest. Although they may not always bite, they can swim towards you or use ramming techniques in order to chase you out of their territory.
The most important thing to remember when you are invading their territory is that you are a threat to them as you are a foreign being in their sea world. Unfortunately, some divers are stupid enough to aggressively attack them or hit them with pointy sticks or knives. Obviously, this will simply aggravate them and the titan triggerfish will learn that divers and snorkellers are dangerous and attack human beings even when they are not provoked.