Undulated Triggerfish

The Undulated Triggerfish is a strikingly beautiful but notoriously aggressive species, widely considered the single most aggressive triggerfish commonly available in the marine aquarium trade. Its body is a deep green to dark olive, covered with a network of bright orange wavy lines that undulate across the entire body and fins, creating a pattern of extraordinary visual intensity. The eyes are ringed in orange, and a dark bar runs from the eye to the pectoral fin base. When viewed under proper lighting, the interplay of green and orange is truly spectacular.

In the wild, the Undulated Triggerfish is a solitary, territorial predator found on coral reefs across the Indo-Pacific. It is extremely aggressive toward other reef fish and fiercely defends a large territory. Its powerful jaws are used to crush sea urchins, crabs, mollusks, and hard corals, and it is known to bite divers and snorkelers who venture too close to its territory or nesting site. This level of aggression translates directly to the aquarium environment.

The Undulated Triggerfish represents the ultimate challenge in triggerfish keeping. It is arguably the most aggressive commonly kept marine aquarium fish, surpassing even the Titan Triggerfish and Clown Triggerfish in sustained hostility toward tankmates. Adult specimens have been known to kill fish nearly their own size, bite through heater cords, shatter glass thermometers, and attack the hands and arms of their keepers during maintenance. Only the most experienced aquarists with very large, heavily built fish-only systems should consider this species. Despite these warnings, its extraordinary beauty and undeniable personality make it a bucket-list fish for many hardcore marine enthusiasts.