Two trigger fish attack scuba diver, underwater video.

Triggerfishes are about 40 species of often brightly colored fishes of the family Balistidae. The largest member of the family, the stone triggerfish (Pseudobalistes naufragium) reaches 1 metre (3.3 ft), but most species have a maximum length between 20 and 50 centimetres (7.9 and 19.7 in). On Koh Tao you can see a lot of Titan triggerfish (up to 50 cm.).

The titan triggerfish can move relatively large rocks when feeding and is often followed by smaller fish, in this case orange-lined triggerfish and moorish idol, that feed on leftovers. Triggerfish males are fierce in guarding their territories as having a territory is essential for reproduction. A male’s territory is used for spawning and parental care. Most male territories are located over a sandy sea bottom or on a rocky reef. A single territory usually includes more than one female, and the male mates with all of the females residing in or visiting his territory (polygyny).