All fish / Balistidae

Bluelined Triggerfish

Xanthichthys caeruleolineatus

Also known as blue lined triggerfish, blue-lined triggerfish, bluelined trigger, blue line trigger, outrigger triggerfish, blueline triggerfish, アオスジモンガラ, 蓝纹炮弹, 蓝线鳞鲀

This is a deep-water trigger from outer reef drop-offs, with a bluish-grey to brown body and a single bright blue line running along the side. Like other Xanthichthys it eats plankton, so it is one of the calmer triggers, and keepers value it as a rarely seen showpiece.

Care at a glance

Care level

Moderate

Temperament

Semi

Adult size

30 cm

Temperature

23 to 27 °C

pH

8.1 to 8.4

Smallest tank

700 litres

Keep as

Singly, one Xanthichthys per tank unless a known pair

Diet

Carnivore: zooplankton feeder; mysis, krill, chopped seafood, quality marine pellets, several feeds a day

Swims

Middle of the tank

Lifespan

10 to 15 years

Water

Marine (saltwater)

Wild range

Indo-Pacific: Red Sea and East Africa to the Line Islands and Hawaii; deep outer reef slopes

Breeding

In the wild it lays eggs in a nest on the bottom, and the eggs are guarded. Breeding in home aquariums has not been reported.

Good to know

It grows large and needs plenty of swimming room. Because it is collected from deep water it is rare and costly, and it may nip at invertebrates or attack other planktivorous triggers.