TankBud

Convict tang

Acanthurus triostegus

Also known as Convict Surgeonfish, Manini, Fiveband Surgeonfish

SaltwaterFish

Convict tang (Acanthurus triostegus)
brian.gratwicke · CC BY 2.0

Care at a glance

Temperature
75–82°F
24–28°C
pH
8.1–8.4
Adult size
10.6 in
27 cm
Minimum tank
124 gal
470 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Middle
Diet
Omnivore
Difficulty
Medium
Breeding
No record
Rarity
Common
Reef safe
Reef safe
Family
Acanthuridae
Origin
Indo-Pacific and eastern Pacific reefs, from East Africa to Central America

Overview

The convict tang is one of the calmest tangs available, an active swimmer for a large reef tank. It is a step up from the easiest marine fish.

Did you know

Hawaiians call the convict tang manini. The word has drifted into local slang to mean stingy or insignificant. A modest-sized manini was a meager catch next to bigger reef fish.

Caring for the convict tang

Give convict tangs a long, open lane for cruising and mature live rock to graze. They need at least 124 gal (470 L), and a proper school needs considerably more room.

Keep the water at 75 to 82°F (24 to 28°C) with a pH of 8.1 to 8.4. A convict tang can still pick up marine ich under stress. Quarantine new arrivals, since its mild temperament does not make it any hardier than the rest of the family.

Feed nori and dried seaweed often, because its wild diet is almost entirely filamentous algae. Offer meaty frozen food as a supplement rather than a staple.

The convict tang does better with company. A group introduced together will shoal peacefully. A lone fish added to a tank with other surgeonfish is more likely to be bullied than to start trouble. It is reef safe with corals and invertebrates.

Good to know

Acanthurus triostegus carries the same folding tail spine as other surgeonfish, but it is far less inclined to use it. It is named for the five to six vertical black bars across its silvery-white body. Most convict tangs seen on the reef are closer to 17 cm, well short of full size.

In the wild

The convict tang is one of the most widely distributed reef fish in the world. It ranges from East Africa across the Indo-Pacific to Central America. Juveniles crowd shallow tide pools and reef flats, then adults move out to lagoons and seaward reefs down to 90 m. Large feeding schools can overwhelm territorial damselfish by sheer numbers, which also spreads out the risk from any one predator.

Weekly picks

Tank mates

The convict tang is a peaceful, schooling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a convict tang need?

A convict tang needs at least 124 gal (470 L). It spends most of its time in the middle.

What temperature and pH does a convict tang need?

A convict tang is comfortable at 75–82°F (24–28°C) with a pH of 8.1–8.4.

What does a convict tang eat?

A convict tang eats nori and dried seaweed, which should be offered often. Meaty frozen food works as a supplement, not a staple.

How big does a convict tang get?

An adult convict tang reaches about 10.6 in (27 cm).

Does a convict tang need a group?

Yes. A convict tang is a schooling species and should be kept in a group, not singly.

Related species