Description

The Orange Shoulder Tang (Acanthurus olivaceus) is a large, active, and visually striking tang species known for its dramatic color change from juvenile to adult. It’s a peaceful algae grazer ideal for larger reef or fish-only aquariums and does best in established systems with ample swimming space.

🐟 Orange Shoulder Tang Description:

• Scientific Name: Acanthurus olivaceus

• Common Names: Orange Shoulder Tang, Orangeband Surgeonfish

• Origin: Indo-Pacific (Hawaii, Indonesia, Fiji, and surrounding regions)

• Size: Up to 14 inches (35 cm) as an adult

• Coloration:

  • Juvenile: Bright yellow with an orange shoulder patch

  • Adult: Changes to grayish-blue body with a vivid orange band behind the eye and bordered in dark gray or black

• Temperament: Peaceful to semi-aggressive (especially with other tangs)

• Lifespan: 10+ years with proper care

🧪 Tank Requirements:

• Minimum Tank Size: 180 gallons (they grow large and are strong swimmers)

• Water Temperature: 74–80°F (23–27°C)

• pH Level: 8.1–8.4

• Specific Gravity: 1.020–1.025

• Water Hardness: 8–12 dKH

• Aquascape: Open swimming areas plus rockwork for grazing and hiding

🥬 Diet:

• Primarily Herbivorous:

  • Nori (dried seaweed)

  • Spirulina-based flakes or pellets

  • Algae sheets and clips

  • Will also eat mysis and brine shrimp but protein should be supplemental

Feed multiple times daily to support its active metabolism and prevent aggression.

🤝 Compatibility:

• Reef Safe: Yes – won’t harm corals or invertebrates

• Tankmates:

  • Gets along well with most peaceful and semi-aggressive fish

  • May be aggressive toward other tangs (especially those in the Acanthurus genus or similarly shaped)

  • Best kept as the only tang in smaller systems unless tank is 300+ gallons

⚠️ Special Notes:

• Like all tangs, it has a sharp scalpel spine at the base of its tail—used for defense

• Prone to marine ich and other parasites—quarantine recommended

• Requires high oxygenation and good flow

• Color transition from yellow (juvenile) to gray-blue (adult) is natural and permanent

📝 Summary: