TankBud

Picasso triggerfish

Rhinecanthus aculeatus

Also known as Humu Picasso Triggerfish, Lagoon Triggerfish, Blackbar Triggerfish, White-banded Triggerfish

SaltwaterFish

Picasso triggerfish (Rhinecanthus aculeatus)
Arpingstone · Public domain

Care at a glance

Temperature
72–79°F
22–26°C
pH
8.1–8.4
Adult size
11.8 in
30 cm
Minimum tank
180 gal
680 L
Temperament
Aggressive
Social behavior
Solitary
Own kind
One per tank
Tankmates
With caution
Swim level
Middle
Difficulty
Medium
Breeding
No record
Rarity
Very common
Reef safe
Not reef safe
Family
Balistidae
Origin
Indo-Pacific, from the Red Sea and East Africa to Hawaii and the Marquesas and Tuamotu islands, north to southern Japan, with a separate population in the eastern Atlantic from Senegal to South Africa

Overview

The Picasso triggerfish is one of the more outgoing triggers, quick to recognize its keeper and beg at feeding time. It is also aggressive and not reef safe, so it is best kept by someone with a little experience.

Did you know

The Picasso triggerfish often carries the humu nickname, but it is not the true Hawaiian state fish, humuhumunukunukuapuaa. That title belongs to its close relative, the reef triggerfish. The two are confused so often that the humu name has stuck to the Picasso as well.

Caring for the Picasso triggerfish

Give a Picasso triggerfish a long tank of at least 180 gal (680 L), with open swimming room and a sand bed it can rearrange. It digs up the sand and knocks over loose rockwork, so wedge the rocks in tight where it cannot topple them.

Keep the water at 72 to 79°F (22 to 26°C) with a pH of 8.1 to 8.4. Feed a varied carnivore diet, with something hard-shelled such as clams or crab several times a week. The hard food helps wear down its teeth, which never stop growing.

Keep only one Picasso per tank and choose its tank mates with caution. It is aggressive and will harass, injure or kill smaller and slower fish, and it grows bolder and more territorial with age. It is not reef safe and eats snails, crabs, shrimp and small bivalves on sight.

The Picasso is not venomous, but it can bite hard enough to break skin. Keep your hands out of the tank during its aggressive moods, and take care during maintenance.

Good to know

The Picasso triggerfish, Rhinecanthus aculeatus, is a triggerfish in the family Balistidae, also sold as the lagoon or blackbar triggerfish. It is named for the bold tan, black and blue markings on its face, which read like an abstract painting. Like all triggerfish, it has a first dorsal spine that a second, smaller spine locks upright until released. That lets it wedge itself into a crevice and become almost impossible to pull out.

In the wild

Picasso triggerfish live across the Indo-Pacific, with a separate population in the eastern Atlantic from Senegal to South Africa. They are found in shallow lagoons, tide pools and reef flats, from the surface down to about 50 meters. In the wild they are omnivores, eating algae, worms, mollusks, sea urchins and small fish. They patrol sandy patches near the reef and blow jets of water into the sand to uncover buried prey.

Common questions

What size tank does a Picasso triggerfish need?

A Picasso triggerfish needs at least 180 gal (680 L). It spends most of its time in the middle.

What temperature and pH does a Picasso triggerfish need?

A Picasso triggerfish is comfortable at 72–79°F (22–26°C) with a pH of 8.1–8.4.

What does a Picasso triggerfish eat?

A Picasso triggerfish eats a varied carnivore diet in the tank. Give it something hard-shelled, such as clams or crab, several times a week to wear down its teeth.

How big does a Picasso triggerfish get?

An adult Picasso triggerfish reaches about 11.8 in (30 cm).

Related species