During diving on Koh Tao we can encounter two species of triggerfish on every dive site - Titan Triggerfish and Yellow Margin Triggerfish, especially on Green Rock divesite, next to Nang Yuan Island, where they have their “nests”.

Instructors of our dive center Scuba Birds can help you to identify them by their large heads, “trigger-like” dorsal fin, and protruding incisor teeth. There are approximately 40 species of triggerfish all over the world and PADI Underwater Naturalist course in Koh Tao could help you with identification.

Triggerfish are by far one of the more intelligent species in the aquatic world. The majority of the time they’re just digging out their prey such as worms and crabs by flapping away debris with their fins. They are one of the only fish here that can be seen using coral, rocks, other debris as tools to open tougher shelled prey. They can also spit water and sand into holes to disorientate their prey. If you have your PADI Digital Underwater Specialty course you could take a lot of really nice pictures.
Triggerfish can become aggressive in a very short time on Koh Tao dive sites, especially on Green Rock and South West pinnacle. They want to protect their nests, usually in the sand, and the larger surrounding area above it from other fish and divers simply passing by. Please treat them with respect, while scuba diving in Koh Tao, we are only guests in their world.

Diving in Koh Tao on Japanese Garden with Titan Triggerfish