The Orangeshoulder Tang (Acanthurus olivaceus), also known as the Orange-Epaulette Surgeonfish, Orangeband Surgeonfish, or Orangespot Surgeonfish, is a striking and dynamic species that transforms dramatically as it matures. Juveniles display a bright, pure-yellow body accented by soft blue edging along the dorsal and anal fins. As the fish reaches adulthood, its coloration shifts: the front half becomes a soft light gray, while the rear deepens into a rich blue-gray tone, creating a bold two-tone contrast unique to this species.
A distinctive orange shoulder stripe—outlined in darker gray—appears above the pectoral fin and becomes the defining feature of mature individuals. The tail also evolves into a subtle lyre-shaped form, adding elegance to its movement. This species is active, graceful, and exceptionally eye-catching in large marine displays.
Minimum Tank Size: 180+ gallons
Temperament: Semi-aggressive (generally peaceful toward other tangs)
Reef Safe: Yes
Behavior: Active swimmer; requires strong flow and open space
The Orangeshoulder Tang thrives in spacious systems with plenty of open swimming room, stable water parameters, and enriched oxygenation. It is more tolerant of other tang species compared to most Acanthurus tangs. When housing multiple Orangeshoulders, adding a juvenile alongside an adult often reduces territorial disputes.
Like most surgeonfish, the Orangeshoulder Tang requires a diet rich in marine-based algae to maintain long-term health and immunity. While they will accept meaty foods, their primary nutrition should come from:
Seaweed/Nori sheets
Spirulina-based pellets & flakes
Macroalgae (Chaeto, Gracilaria)
Marine algae blends
Feeding algae 3–4 times weekly helps reduce aggression and supports vibrant coloration.
Recommended products: Sea Veggies, Seaweed Salad, Ocean Nutrition.
Large reef aquariums (180+ gallons)
Mixed tang communities (with careful introduction)
Hobbyists wanting a unique, color-shifting show fish
Systems needing active algae grazers
The Orangeshoulder Tang (Acanthurus olivaceus), also known as the Orange-Epaulette Surgeonfish, Orangeband Surgeonfish, or Orangespot Surgeonfish, is a striking and dynamic species that transforms dramatically as it matures. Juveniles display a bright, pure-yellow body accented by soft blue edging along the dorsal and anal fins. As the fish reaches adulthood, its coloration shifts: the front half becomes a soft light gray, while the rear deepens into a rich blue-gray tone, creating a bold two-tone contrast unique to this species.
A distinctive orange shoulder stripe—outlined in darker gray—appears above the pectoral fin and becomes the defining feature of mature individuals. The tail also evolves into a subtle lyre-shaped form, adding elegance to its movement. This species is active, graceful, and exceptionally eye-catching in large marine displays.
Minimum Tank Size: 180+ gallons
Temperament: Semi-aggressive (generally peaceful toward other tangs)
Reef Safe: Yes
Behavior: Active swimmer; requires strong flow and open space
The Orangeshoulder Tang thrives in spacious systems with plenty of open swimming room, stable water parameters, and enriched oxygenation. It is more tolerant of other tang species compared to most Acanthurus tangs. When housing multiple Orangeshoulders, adding a juvenile alongside an adult often reduces territorial disputes.
Like most surgeonfish, the Orangeshoulder Tang requires a diet rich in marine-based algae to maintain long-term health and immunity. While they will accept meaty foods, their primary nutrition should come from:
Seaweed/Nori sheets
Spirulina-based pellets & flakes
Macroalgae (Chaeto, Gracilaria)
Marine algae blends
Feeding algae 3–4 times weekly helps reduce aggression and supports vibrant coloration.
Recommended products: Sea Veggies, Seaweed Salad, Ocean Nutrition.
Large reef aquariums (180+ gallons)
Mixed tang communities (with careful introduction)
Hobbyists wanting a unique, color-shifting show fish
Systems needing active algae grazers
