Species group: Triggerfish
Other common names: Blue Chin; Blue Throat
Scientific name: Xanthichthys auromarginatus
The Blue Jaw Triggerfish gets its name from the large blue patch seen in males. The females are not as colorful as the males and are known as Gilded Triggerfish. These fish do not grow to a very large size and are one of the smallest of Xanthichthys fish. The mouth is slightly upturned which is suited for feeding on free-floating zooplankton.
The Blue Jaw Triggerfish, especially males, are quite aggressive with other fish. They are rather hardy and disease resistant. They generally ignore most invertebrates such as starfish, snails, and shrimp. If the Xanthichthys is the last fish in the aquarium, little trouble can be expected. Smaller fish may feel threatened in the presence of the Blue Jaw and may tend to hide constantly.
The Blue Jaw, though small compared to other Triggerfish, requires a large tank since it requires a lot of space to swim. Small Gilded Triggerfish require a tank of at least 40 gallons, while an adult requires a 100-gallon tank. They enjoy good water movement, and hence a small area of the tank could be dedicated to water jets and bubbles. Servings of shrimp, mussels, squid, and fish may be a good diet for the Blue Jaw. The ammonia and nitrite levels need to be extremely low.