Xantyhicthys mento/auromarginatus - Truly 1 of a kind.
This is one of the less aggressive members of the family. It feeds on zooplankton. It can be kept with moderately-aggressive tankmates and can even be kept in groups (one male and one or more females) in extra large aquariums. This trigger rarely bothers its tankmates. Like many triggers, it is often shy when first added to the aquarium, but becomes bolder as it learns to associate its caretaker with food. Being a planktivore, it will not harm corals in the reef aquarium.
These triggers are suitable for large (180 gal) fish only or reef tanks. They are big!