Kingdom: Animalia

Phylum: Chordata

Class: Actinopterygii

Order: Tetraodontiformes

Family: Balistidae

Genus: Odonus

Species: O. niger

Physical Description

The Redtoothed Triggerfish is also known as the Niger Triggerfish, the Black Triggerfish, the Blue Triggerfish and the Purple Triggerfish.  The color varies from blue to purple to black, even on the same specimen and the teeth are reddish. It lives in reef channels and areas of strong current in the central and western Pacific and in the Red Sea.  It has a distinctive lyre tail.  Triggerfish have a double dorsal fin with a large spine or trigger in the front area of the fin. It uses the spine to lock itself into rocks and corals where it sleeps for the night, well protected from predators.

Biology and Behavior

These fish are aggressive towards others of their species and can vocalize making a grunting-type sound. They have the ability to change the color of their body from purple to blue to blue-green depending on their mood. Holes are hiding spots in which they lock themselves into by using the tail as a hook and the dorsal fin as a wedge. Mucous covers the body that is secreted from the skin and provides protection from parasites and helps these triggerfish swim faster. Aggression and aggravation are vocally expressed to others of their species by making a loud grunting sound. The bodies change coloration to warn potential predators to stay away or to attract a mate. Triggerfish are showing a warning when the dorsal fin is raised and locked into the erect position. These usually solitary fish meet at mating grounds where males establish territories. Nests are prepared into which eggs are laid; they are guarded and cared for until they hatch.

Habitat and Distribution

Inhabits reef channels or along slopes that are subject to strong currents Occur in current-swept seaward coral reefs. Can be seen in coral reefs of the Indo-Pacific. In Australia it is known from the offshore reefs of north-western Western Australia and from the entire length of the Great Barrier Reef.


Red-toothed triggerfish