Orangeshoulder Tang

Acanthurus olivaceus

Also known as Orangeband Surgeonfish, Orange-shoulder Surgeonfish, Orangebar Tang

SaltwaterFish

Care at a glance

Temperature
75–82°F (24–28°C)
pH
8.1–8.4
Adult size
13.8 in (35 cm)
Minimum tank
180 gal (680 L)
Temperament
Mostly peaceful
Social behavior
Solitary
Swim level
Middle
Difficulty
Medium
Breeding
No record
Rarity
Common
Reef safe
Reef safe
Origin
Indo-Pacific reefs, from Christmas Island to Hawaii and southern Japan
Family
Acanthuridae

Overview

Semi-aggressive toward other tangs and surgeonfish but milder about it than many Acanthurus species, and generally easygoing with unrelated fish. Reef safe with corals and invertebrates. It grazes algae film and detritus off the substrate in the wild, so in the aquarium it needs regular nori or dried seaweed plus a steady supply of meaty frozen food to keep condition and reduce squabbling over food. Like other tangs it is vulnerable to marine ich when stressed, so give new arrivals a full quarantine before adding them to the display.

In the wild

Found on Indo-Pacific reefs from Christmas Island to Hawaii and southern Japan, with adults grazing sandy and rubble bottoms between about 9 and 46 m while juveniles shelter in shallower, more protected water. It is one of the larger tangs in the trade, so it needs a long tank with a wide-open swimming lane plus rockwork carrying a healthy film of algae. Give it at least 680 litres (180 US gal), since it outgrows a standard 125-gallon setup.

Good to know

Carries the folding scalpel spine common to the genus Acanthurus at the base of the tail, used mainly against other tangs defending territory. It is a big grower for a reef tang, with a recorded maximum around 35 cm even though most aquarium specimens top out closer to 25 cm. Juveniles are solid yellow and easy to mistake for a young yellow tang; the grey body and orange comma-shaped shoulder patch that give the species its name only appear as it matures.

Did you know

Juveniles are such a close match for young yellow tangs that they are often mistaken for one another in dealer tanks, and the giveaway only shows up once the fish matures and its color splits into grey front, blue-grey back, and that bright orange shoulder stripe.

Where to buy

Some links may not be the exact species or variety.

…or ask your local fish store.

Appears in

Saltwater fish · Tangs & surgeonfish · Reef-safe fish

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