Goldrim Tang - Acanthurus Japonicus

Goldrim Tang (Acanthurus japonicus)

The Goldrim Tang, Acanthurus japonicus, is a beautiful and highly desirable marine surgeonfish, admired for its rich brown to charcoal body colour, bright white facial marking, golden fin highlights and elegant swimming behaviour. Also commonly known as the Powder Brown Tang, Japan Surgeonfish or White-Faced Surgeonfish, this species brings constant movement and natural algae-grazing behaviour to large mature reef aquariums. It is best suited to experienced marine fishkeepers, as it requires excellent water quality, strong oxygenation, plenty of swimming space and careful introduction.

Common Name:
Goldrim Tang, Powder Brown Tang, Japan Surgeonfish, Japanese Surgeonfish, White-Faced Surgeonfish, Whitecheek Tang.

Scientific Name (Latin):
Acanthurus japonicus

Maximum Size:
Up to around 21 cm, making it a medium-sized surgeonfish that requires strong swimming space and long-term planning.

Water Type:
Marine

Origin / Natural Habitat:
Found in the Western Pacific, including southern Japan, the Ryukyu Islands, Taiwan, the Philippines, Indonesia and surrounding reef regions. In the wild, Goldrim Tangs inhabit clear lagoon reefs and seaward reefs, usually in shallow exposed areas with strong water movement and plenty of algae-covered hard surfaces. They may be found alone or in small to large groups, grazing across reef surfaces throughout the day.

Water Parameters:
Temperature: 24–27°C
pH Range: 8.1–8.4
Hardness or Salinity: SG 1.020–1.025

Temperament:
Semi-aggressive. Goldrim Tangs can be territorial, especially towards other tangs, surgeonfish and similarly shaped algae grazers. They are usually best kept as the only Acanthurus tang unless the aquarium is very large and carefully planned. Suitable tank mates include peaceful to moderately robust marine fish that will not bully or heavily outcompete them.

Diet:
Primarily herbivorous grazer. In the wild, this species feeds heavily on algae from reef surfaces. In the aquarium, offer frequent feeds of marine algae sheets, nori, spirulina flakes, herbivore pellets, algae-based frozen foods and quality marine grazing foods. Small amounts of frozen mysis, enriched brineshrimp and finely chopped marine foods can also be offered, but the diet should remain strongly algae-focused. Regular feeding is important to support immune health, body condition and colour.

Minimum Tank Size:
A minimum of around 450–500 litres is recommended for a single specimen, with larger aquariums strongly preferred for long-term success. A long aquarium with open swimming lanes, mature rockwork, strong filtration and good oxygenation is far more suitable than a small or cramped system.

Behaviour & Activity:
An active daytime swimmer and constant grazer that spends much of its time moving around the aquarium, picking at algae films and exploring rockwork. Goldrim Tangs appreciate strong water movement, open swimming areas and mature live rock for grazing. Like other surgeonfish, they have a sharp caudal peduncle spine near the tail, which can be used defensively. A secure lid is recommended, as startled marine fish can jump.

Reef Safe:
Reef Safe
Goldrim Tangs are considered reef safe and do not normally nip corals or clam mantles. They are useful algae grazers in mature reef aquariums, although they should not be relied upon as the only algae-control method. Their reef suitability depends heavily on providing enough space, stable water quality and a strong algae-based diet.

Special Requirements or Care Notes:
Best suited to experienced marine fishkeepers. Goldrim Tangs can be sensitive to stress, poor water quality and unstable conditions, and they are often considered more delicate than hardier tang species. Quarantine, careful acclimation and a mature, well-oxygenated aquarium are strongly recommended. Avoid adding to newly set up systems, overcrowded aquariums or tanks with aggressive tangs already established. Provide regular algae-based feeding and plenty of swimming space to reduce stress.

Suitable for:
Experienced fishkeepers

Availability:
Premium marine species / Availability can vary depending on collection, import, size and supplier

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.