The triggerfish come in a variety of different colors combinations. Some of these are truly stunning. While the niger triggerfish (Odonus niger) is not the most colorful in the group, it is an elegant fish with an intriguing set of dentures. The teeth of the adult niger triggerfish are blood red (one of the commonly used vernacular names for this species is redtooth triggerfish). The niger triggerfish also has some attributes that make it more suitable for aquarium communities than most triggerfish.
Difficulty: The niger triggerfish is a durable aquarium species. That said, juvenile niger triggerfish acclimate more rapidly to captive living than large adult niger triggerfish. If a large O. niger is added to an aquarium, it will remain more secretive and shy for a longer period of time, and some individuals will never fully trust their keeper. The niger triggerfish needs to be fed often: at least two or three times a day. Feed it a variety of frozen foods, including mysid shrimp, krill and preparations for carnivores. Fresh or frozen seafood that has been grated or chopped to an ingestible size should also be on the menu.
Physical description: The niger triggerfish is truly an elegant triggerfish. The adult niger triggerfish have long streamers that flow from the upper and lower lobes of the tail. The overall color of the niger triggerfish varies from a deep purple to dark green. The niger triggerfish often has a light gray face. The niger triggerfish can reach a maximum length of 19 inches, but without the tail filaments, most do not exceed 10 inches.
Range: The niger triggerfish ranges from the Red Sea and east Africa, east to the Society Islands. It is found at a depth of 15 to 130 feet. The niger triggerfish is typically found in current-swept areas of fore reef slopes, where it forms large aggregations and feed on passing zooplankton.
Compatibility: The young niger triggerfish is usually not overly aggressive. The niger triggerfish may defend a preferred hiding place, but it does not roam about the aquarium looking for trouble. Most adult niger triggerfish kept in community aquariums with similarly sized fish will ignore their neighbors, but some large adult niger triggerfish may start chasing and nipping at tankmates. It is a good idea to add the niger triggerfish last to an aquarium full of moderately aggressive fish species, as individuals that are well-established are more likely to nip at newly introduced tankmates. More than one niger triggerfish can be kept in the same aquarium if they are added simultaneously and the aquarium is large enough (at least 200 gallons). Juvenile niger triggerfish tend to get along better with one another than adults (males may fight to the death). This is one of a handful of triggerfish than can be kept in a reef aquarium. Niger triggerfish rarely bother corals, but an occasional individual may nip at ornamental crustaceans and snails. If you want to attempt to keep a cleaner shrimp with your triggerfish, add the crustacean before the triggerfish.
Aquarium conditions: The adult niger triggerfish will need a spacious aquarium with plenty of open swimming space. An aquarium of at least 135 gallons is preferable for an adult niger triggerfish. An even larger aquarium will help prevent aggression problems that are sometimes associated with large adult niger triggerfish. Keep water parameters for the niger triggerfish at a pH of 8.1 to 8.4, a specific gravity of 1.019 to 1.025 and a water temperature of 74 to 82 degrees.
Care considerations: Before you take decor out of an aquarium that contains a niger triggerfish, it is a good idea to figure out where the O. niger is. I have seen cases where a piece of coral or rock was removed without the aquarist realizing the triggerfish was in a crack or between coral branches.
Breeding: The niger triggerfish is not likely to spawn in the home aquarium. The niger triggerfish species is known to be a protogynous hermaphrodite.