Whitecheek Tang

Whitecheek Tang

The Whitecheek Tang (Acanthurus nigricans), also called the gold-rim or powder-black surgeonfish, is a handsome, dark-bodied tang accented by a bright white patch beneath the eye, yellow margins on the dorsal and anal fins, and a yellow-flushed caudal spine. Active and attractive, it is a popular reef-safe grazer — though it has a reputation for being somewhat delicate and prone to ich, which places it a notch above the easiest tangs in terms of care.

It is a rewarding fish for the keeper who can provide a large, stable, well-run system.

Natural Habitat & Origin

Acanthurus nigricans is widespread across the Pacific and into the Indian Ocean, where it grazes algae over clear-water outer reefs and reef crests with good water movement. It ranges over the reef as it feeds, favouring oxygen-rich, high-energy zones.

In the aquarium it wants open swimming space, abundant live rock for grazing, and strong, well-oxygenated water movement.

Care Requirements

Maintain stable marine conditions: salinity around 1.024–1.026, pH 8.1–8.4, and a temperature of about 24–26°C (75–79°F), with good flow and high oxygen. Reaching about 21 cm (8 inches), it is an active fish that needs a tank of around 340 litres (about 90 US gallons) or more for swimming and grazing. Stable, pristine water quality is especially important, as this species is sensitive to deteriorating conditions.

Diet & Feeding

The Whitecheek Tang is a herbivore that grazes on algae in the wild. Offer a primarily plant-based diet: dried marine algae (nori) on a clip, herbivore and spirulina preparations, and algae-based frozen foods, with occasional meaty items. Frequent small feedings suit its constant grazing, and good algae growth on mature live rock provides valuable grazing between meals — important for keeping this sometimes-finicky fish in condition.

Behavior & Temperament

Like other surgeonfish, it is semi-aggressive and territorial, particularly toward other tangs. It is best kept as the only tang in all but very large systems, and introduced thoughtfully. Its sharp caudal spine is a defensive weapon, so handle with care. Toward unrelated fish it is generally manageable.

Tank Mates

House it with robust marine fish in different niches — wrasses, angelfish, larger gobies and anthias — in a tank large enough to dilute aggression. Avoid other tangs unless the system is very large. It is reef-safe, grazing algae rather than corals or invertebrates, making it a good choice for a large reef.

Breeding

Acanthurus nigricans is a pelagic spawner with planktonic larvae and is not bred in the home aquarium. Trade specimens are wild-collected.

Common Health Issues

The Whitecheek Tang is notably susceptible to marine ich (Cryptocaryon irritans) and marine velvet (Amyloodinium ocellatum), especially when stressed by capture and shipping, and it ships and acclimates less robustly than some tangs. A careful quarantine and a stable, oxygen-rich, low-stress environment are essential. Provide pristine water, strong flow and a varied herbivorous diet, choose a feeding specimen, and this striking tang can be a rewarding reef-safe grazer for an experienced keeper.