Orangeshoulder Tang
Acanthurus olivaceus
Also known as Orangeband Surgeonfish, Orange-shoulder Surgeonfish, Orangebar Tang
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
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Related species

Atlantic Blue Tang
Acanthurus coeruleus13.8 in (35 cm)151 gal (570 L)75–81°F (24–27°C)
Whitecheek Tang
Acanthurus nigricans13.8 in (35 cm)129 gal (490 L)75–81°F (24–27°C)
Mimic Tang
Acanthurus pyroferus11.4 in (29 cm)129 gal (490 L)75–82°F (24–28°C)
Powder Brown Tang
Acanthurus japonicus8.3 in (21 cm)129 gal (490 L)75–81°F (24–27°C)
Clown Tang
Acanthurus lineatus15 in (38 cm)238 gal (900 L)75–81°F (24–27°C)
Sohal Tang
Acanthurus sohal15.7 in (40 cm)180 gal (680 L)75–82°F (24–28°C)
