TankBud

Undulated triggerfish

Balistapus undulatus

Also known as Orange-lined triggerfish, Orangetail triggerfish, Undulate triggerfish, Vermiculated triggerfish

SaltwaterFish

Undulated triggerfish (Balistapus undulatus)
Diego Delso · CC BY-SA 4.0

Care at a glance

Temperature
75–81°F
24–27°C
pH
8.0–8.4
Adult size
11.8 in
30 cm
Minimum tank
180 gal
680 L
Temperament
Aggressive
Social behavior
Solitary
Own kind
One per tank
Tankmates
Species tank only
Swim level
Middle
Diet
Carnivore
Difficulty
Difficult
Breeding
Substrate spawner
Rarity
Common
Reef safe
Not reef safe
Family
Balistidae
Origin
Native to the Indo-Pacific and Red Sea, living on coral reefs where it patrols a territory around rock and coral heads.

Overview

The undulated triggerfish is a beautiful reef trigger with a reputation as the meanest triggerfish in the sea. It needs a big fish-only tank and is for experienced keepers.

Did you know

The undulated triggerfish is so aggressive that a resident one will attack almost anything new that arrives in its tank, regardless of size.

Caring for the undulated triggerfish

Keep an undulated triggerfish only in a fish-only tank of at least 180 gal (680 L). It uses its strong teeth to crush shells and rearrange rockwork, so build sturdy rockwork it cannot topple. Hold the water at 75 to 81°F (24 to 27°C) and a pH of 8.0 to 8.4.

Feed hard-shelled meaty foods such as clams, mussels and shrimp in the shell, which keep its teeth worn down. It is not reef safe. It eats shrimp, crabs, snails, urchins and clams, and it nips corals.

Keep a single undulated triggerfish on its own in a species tank. It is widely rated the most aggressive of all triggerfish, and it can bully fish far larger than itself.

Females lay their eggs in a nest scraped into the substrate. They guard the eggs and defend them fiercely.

Good to know

The undulated triggerfish, Balistapus undulatus, is a dark green fish crossed by wavy orange lines, with a bright orange band across the tail base. It is also sold as the orange-lined or orangetail triggerfish. It can lock itself into a crevice by raising its first dorsal spine and bracing a second spine behind it. This trigger mechanism is what gives the family Balistidae its name.

In the wild

Undulated triggerfish are native to the Indo-Pacific and the Red Sea. They live on coral reefs, where each one patrols a territory around rock and coral heads.

Common questions

What size tank does an undulated triggerfish need?

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

What temperature and pH does an undulated triggerfish need?

An undulated triggerfish is comfortable at 75–81°F (24–27°C) with a pH of 8.0–8.4.

What does an undulated triggerfish eat?

An undulated triggerfish eats hard-shelled meaty foods such as clams, mussels and shrimp in the shell. The shells keep its teeth worn down.

How big does an undulated triggerfish get?

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

How does an undulated triggerfish breed?

Undulated triggerfish lay their eggs in a nest scraped into the substrate. The female guards the eggs and defends them fiercely.

Related species