Clown Triggerfish

Balistoides conspicillum

Also known as Bigspotted Triggerfish, Yellow-blotched Triggerfish, Clown Trigger

SaltwaterFish

Clown Triggerfish (Balistoides conspicillum) — Amada44 · CC BY-SA 3.0

Care at a glance

Temperature: 72–79°F (22–26°C)
pH: 8.1–8.4
Adult size: 19.7 in (50 cm)
Minimum tank: 300 gal (1,135 L)
Temperament: Aggressive
Social behavior: Solitary
Swim level: Middle
Difficulty: Difficult
Breeding: No record
Rarity: Rare
Reef safe: Not reef safe
Origin: Indo-Pacific, from East Africa to Samoa, north to southern Japan, south to New Caledonia
Family: Balistidae

Overview

Clown triggerfish are relatively docile as small juveniles but become steadily more territorial and aggressive as they grow past about 20 cm, and a full grown adult is one of the most aggressive fish commonly kept in the hobby, needing large, robust tankmates like groupers or big angelfish rather than anything small or docile. It is not reef safe in any sense: it eats crustaceans, mollusks, and sea urchins as a matter of course and will treat a reef tank's cleanup crew as a menu. Offer a varied diet of squid, krill, clams, crab, and other meaty foods, including hard-shelled items to keep its continuously growing teeth in check. It is not venomous, but it bites hard and has been known to chip acrylic panels and scratch glass, so tank material and equipment placement matter, and hands should stay well clear of an adult's territory.

In the wild

Found along the inner and outer edges of coral reefs across the Indo-Pacific, usually from about 1 to 75 meters deep, wherever shellfish and other invertebrates are abundant. Juveniles stay hidden in caves and crevices, while adults range more widely to forage. A tank for this species needs to be large enough for a genuine territory, with heavy rockwork secured well enough to withstand a fish that will rearrange it.

Good to know

Balistoides conspicillum is a triggerfish in the family Balistidae and one of the largest and most recognizable in the hobby, reaching about 50 cm. Its pattern changes dramatically with age: juveniles are black and densely covered in small white spots with a yellow-tinged snout, while adults develop large white spots concentrated on the lower body, a yellow-netted back, and a bold white band across the mouth that gives the species its name, conspicillum, Latin for spectacles. A breeding pair digs a nest in sand or rubble, and the female fans and blows bubbles over the eggs to keep them oxygenated while both parents guard the nest for about a week.

Did you know

A juvenile clown trigger barely resembles the adult it will become: the small, crowded white spots and mostly black body of a young fish gradually shift into the bold, widely spaced white polka dots and yellow-netted back of the adult over a year or more.