The Orange Shoulder Tang (Acanthurus olivaceus), also known as the Orangespot Surgeonfish, is a striking and peaceful reef fish that undergoes a fascinating color transformation as it matures. As juveniles, they display a bright yellow coloration which gradually changes to a grayish-blue with a distinctive orange shoulder marking as they reach adulthood. Their active swimming behavior and unique appearance make them a popular choice for larger reef tanks.
 
Average Size: Typically grows up to 14 inches (35 cm).
 
Tank Size: Requires a minimum of 125 gallons due to their large size and high activity levels.
 
Temperament: Peaceful. Generally non-aggressive and can coexist with other non-territorial fish. However, they may become territorial towards other tangs in smaller tanks.
 
Unique Traits: Known for their dramatic color change from vibrant yellow when juvenile to a muted gray with an eye-catching orange shoulder marking when mature. This color transformation is one of their most distinguishing features.
 
Origin: Found in the Indo-Pacific region, particularly around the reefs of Hawaii, Australia, and Fiji.
 
Care Level: Moderate. They are hardy fish but need stable water conditions and a well-maintained tank. Due to their large size, they also require spacious aquariums with plenty of room to swim.
 
Diet: Herbivorous. They primarily feed on algae in the wild. In an aquarium, their diet should consist of marine algae, seaweed sheets, and spirulina. Occasionally, supplementing with mysis shrimp or other meaty foods will benefit their health.
 
Characteristics:
Active swimmers that require open spaces for movement.
Excellent algae grazers, contributing to a clean tank environment.
Shows an interesting and dramatic color change from juvenile to adult.
Peaceful, but can show mild aggression to other tangs or similar species in confined spaces.
Thrives in reef tanks and is generally considered reef-safe.
 
Water Parameters:
pH: 8.1-8.4
gH: 8-12
kH: 8-12
TDS: 350-450 ppm
Temperature: 75-80°F (24-27°C)
 
Disclaimer: "Please note that these are general guidelines, and for more accurate values, we encourage you to contact Living Aquarium by phone or in person. Within store hours, our team of experts are always happy to answer any questions you may have and provide personalized guidance on care."