Saltcorner
By Bob Goemans
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Xanthichthys

Xanthichthys auromarginatus

(Bennett, 1831)

Blue Throat Triggerfish, Gilded Triggerfish, Blue Chin Triggerfish, Blue Jaw Triggerfish

Likely Reef Tank Suitable

Likely Fish-Only Tank Suitable

Range: Indo-Pacific Ocean: East Africa to the Hawaiian Islands, north to the Ryukyu Islands, south to Cocos-Keeling and east to New Caledonia.

Size: 9 inches (22 cm)

Natural Environment: Inhabits the upper areas of current swept seaward reefs containing abundant coral growths and seawhips. Mainly found at moderate depths in these areas, about 70 feet (20 m) in small groups just above bottom areas. Basically a zooplankton feeder in the wild. Seeks caves in the reef structure to hide or rest during evening hours.

General Husbandry: The male in this species has a blue patch that extends from the mouth to the gills, a somewhat tannish body having pale dots, and the light grey dorsal, anal, and tail fin edged in yellow. Females lack the blue throat area and are often referred to as the Gilded Triggerfish. This is one of the smallest and most mild-mannered in the triggerfish family, if not the best, making it a good choice for community-style reef or fish-only aquariums.

In the home aquarium, they require a meaty diet, e.g., fortified brine shrimp, mysis, chopped fish, shrimp, squid, and clam flesh, and/or meaty type frozen carnivore foods with two or three feedings per day highly recommended. Even though many people regard them as reef safe, caution still needs to be taken, as ocassional reports note they annoy small fish, pick on small ornamental shrimp, eat urchins, and nip worms such as feather dusters! Yet corals, soft and stony are not at risk. As to tankmates, except for the most docil and slow moving species, the Blue Throat makes an amenable species.

Keep in mind that generally its recommended not more than one triggerfish be kept per aquarium unless a mated pair, and furthermore, that it be the last fish to be placed into the aquarium.

Taxonomy:

    Order: Tetraodontiformes

    Suborder: Tetraodontoidei

    Family: Balistidae

    Genus: Xanthichthys

FYI: Their common name, triggerfish, comes from their ability to lock and unlock their first dorsal fin. This fin is normally retracted and carried in a groove on the upper body. When frightened, the fish will dart into a crevice or branch of coral and raise this trigger-like fin, securely locking itself into its place of protection.

They should be housed with small pieces of seashells since they like to bite on them or turn them over in the search of prey. Better these shells than other aquarium decor. It also helps keep their teeth worn-down, which actually could get too long and pointed and cause them some difficulty in feeding.

In general, triggerfish are like angelfish and surgeonfishes, as they have laterally compressed bodies with small mouths with strong jaws and chisel-like teeth for crushing hard-shelled prey. However, eyes are set back and located high on their large head to avoid damage when feeding on urchins, one of their favorite foods.

Especially fond of live urchins, which they turn over with jets of water from their mouth, then consume their meaty unprotected bottom areas.

Even though specimen and confines specific, those in the genera Balistes, Balistoides, Pseudobalistes, Rhinecanthus, and Sufflamen are generally thought of as the most aggressive in the Triggerfish family. Those in the Melichthys, Odonus and Xanthichthys genera are more suitable community fish candidates, yet all are not trust worthy when it comes to invertebrates as mentioned above.

Care Level: Easy

Temperament: Semi-aggressive

Diet: Carnivore

Acclimation Time: 15 minutes+

Aquarium Environment: Fish-only and reef aquariums

Coral Safe: Yes

Invertebrate Safe: (See above)

Tankmates: Preferably equal in size

Minimum Tank Size: 100 gallons

Temperature Range: 72 - 82°F (22 – 27°C).

Specific Gravity: 1.020-1.026

pH: 7.9 - 8.5

 Xanthichthys auromarginatus (Blue Throat Triggerfish, Gilded Triggerfish, Blue Chin Triggerfish, Blue Jaw Triggerfish)
Photo © Bob Fenner
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