
Black Triggerfish
Melichthys niger
Balistoides viridescens

The titan triggerfish is the largest triggerfish found across most of the Indo-Pacific, though it is absent from Hawaii. Divers give it a wide berth, since it can be fiercely territorial.
Also known as: blue-finned triggerfish, dotty triggerfish, giant triggerfish, moustache triggerfish, titan triggerfish, bluefin filefish, blue-finned triggerfish, dotty triggerfish, blue finned triggerfish, mustache triggerfish, triggerfish, bluefin triggerfish, moustache triggerfish, titan triggerfish, dotty trigger-fish, leubiem manok
Look for a large, greyish-green triggerfish with a cross-hatched scale pattern, a yellow-green patch on the cheek, and a dark band above the lip like a moustache. This colour pattern is fixed and visible from a distance, and its large size alone sets it apart from other reef triggerfish.
This fish has a greyish-green body with pale edges on each scale, giving it a cross-hatched look. Most of the cheek is covered by a yellow-green patch, and a dark green band runs above the upper lip like a moustache. The base of the tail and the body just in front of it are whitish, and the fins have dark margins. It grows to a maximum length of 75 cm.
The titan triggerfish is active by day and usually solitary. It feeds by turning over rocks and stirring up sand, and by biting off pieces of branching coral, which often draws smaller fish that feed on the scraps it stirs up. It is one of the few reef fish that will hunt and eat crown-of-thorns starfish. It can be aggressive toward other fish that enter its territory, and females guarding eggs have been known to attack divers who come too close.
As the largest triggerfish in its range, a titan triggerfish guarding its nest can become bold enough to attack a diver who swims too close overhead, one of the few reef fish known to behave this way toward people.
Describe what you saw and we name it, then keep every species you find in your Oceandex.