Crosshatch Triggerfish (Xanthichthys mento)
Crosshatch Triggerfish (Xanthichthys mento) known to tropical fish keeping enthusiasts as the Blue Cheekline Trigger, Redtail Triggerfish, or (erroneusly) the Blue Throat Triggerfish is found throughout tropical and sub-tropical Eastern and Western Pacific Oceans. Its range extends from southern Japan, Hawaiian Islands, Clipperton Island, Revillagigedo Islands, to southern California, Easter Island, and Pitcairn Islands.
Crosshatch Triggerfish are one of the rarer benthopelagic species that are encountered in large schools around corals, rocky substrates, drop-offs, and areas with ample hiding spots along the outer seaward coral reefs of oceanic islands and continental slopes of their range at depths from 20 to over 430 ft. They are often found in large schools in open water, usually at depths below 90 feet, feeding on passing zooplanktons.
Crosshatch Triggerfish have the typical triangular shape of other Triggerfish when its fins are erect, similar to other members of the genus Xanthichthys.
Crosshatch Triggerfish (Xanthichthys mento)
Males have straw yellow colored scales outlined in black, that give the body an intense yellow crosshatched look, and a red rimmed tail with neon blue submarginal bands. Females are distinguished by a yellow fringed caudal fin and a slate gray to drab blue body color that runs into the caudal fin. Both sexes have black cris-crossing lines along the body and blue radiating lines on the face.
Because of their innate foraging behavior, Crosshatch Triggerfish, like the Humu Rectangle Triggerfish (Rhinecanthus rectangulus) are not considered reef safe. They will constantly rearrange and disturb rocks and corals in a reef system and prey on invertebrates and crustaceans, making them much more suited for FOWLR tanks.
Crosshatch Triggerfish are best housed in a mature FOWLR tank of at least 125 gallon capacity with a sand or coralline gravel substrate, substantial amounts of live rock formed into caves, crevices, and overhangs for them to hide among, and plenty of free swimming space along the substrate. A good filtration system, protein skimmer and wave maker to replicate the moderate currents in their natural habitat is recommended.
Crosshatch Triggerfish can be housed singly, in pairs, or in groups of one male and two or more females. They have a mild disposition and are unlikely to conflict with other aquarium inhabitants in a large system. Except for small Pseudochromis and other smaller species, they mix well with most other reef fish.
Suitable tankmates that can can coexist with Crosshatch Triggerfish include large angelfish like the Emperor Angelfish (Pomacanthus imperator), peaceful herbivores like Yellow Tangs (Zebrasoma flavescens), Flame Angelfish (Centropyge loricula), Hawaiian Cleaner Wrasse (Labroides phthirophagus), Sohal Tang (Acanthurus sohal), basslets, and other hardy species.
Crosshatch Triggerfish are not commonly aquacultured and have only recently been bred in an aquarium environment. Their relative rarity in the aquarium trade and high, dependable, embryo production make the challenging to raise larvae a worthwhile effort for breeders. Juveniles were successfully raised from captive eggs on ciliates, copepods and artemia.
In their natural habitat, Xanthichthys mento live singly, as pairs, and in small groups or larger schools. They are demersal spawners that become highly territorial during courtship and spawning. Males will establish a territory for spawning to take place which is normally during the early morning hours.
After spawning, anywhere from a thousand to a million 0.48 mm diameter fertilized eggs are scattered along the bottom. The spherical, adhesive eggs that contain multiple oil droplets hatch in the evening into small larvae that begin feeding at 2.1 mm in length. Although both parents guard the offspring, only the females tend to the eggs. In an aquarium environment, the larval stage lasts anywhere from 65 to over 100 days. Crosshatch Triggerfish pairs will spawn approximately every 19-23 days.
In their natural habitat, Crosshatch Triggerfish are an opportunistic benthopelagic species that live and feed near the bottom on benthic, in midwater on passing zooplanktons, and near the surface on a variety of free swimming organisms.
In an aquarium environment, they are not finicky eaters and will consume most aquarium fare including high quality marine pellets, frozen foods, and live or frozen seafood to maintain their health and vibrancy.
Their diet should primarily consist of meaty foods like fresh or frozen chopped whole shrimp, squid, silver sides, mysis shrimp, and clams. Chopped krill is an especially good food that provides the beneficial carotenoids needed to maintain their pigmentation. Feeding small portions several times daily is recommended to maintain body weight.
Crosshatch Triggerfish (Xanthichthys mento) known for their striking colors and intricate pattern of lines are a popular choice among tropical fish keeping enthusiasts. Although they are relatively rare and expensive, thay are occasionally available on waiting lists through specialty fish shops and online retailers like Saltwaterfish.com.
Current prices for 4″ to 5″ males start at around $1300.99.
Crosshatch Triggerfish (Xanthichthys mento)
Minimum Tank Size: 125 gallons
Aquarium Type: FOLR
Care Level: Easy
Temperament: Semi Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 76 to 82°F , dKH 8 – 12°, pH 8.1 – 8.4, sg 1.020-1.025
Max size: 12″
Color Form: Black, Blue, Red, Yellow
Diet: Omnivore
Compatibility: Not reef safe
Origin: Indo Pacific
Family: Balistidae
Lifespan: 8 – 12 years
Aquarist Experience Level: Intermediate
