Black Tang

Black Tang

The Black Tang (Zebrasoma rostratum), sometimes called the longnose black sailfin tang, is one of the most coveted surgeonfish in the marine hobby. Uniformly jet-black from nose to tail, with the tall, sail-like fins typical of its genus and a slightly elongated snout, it is an elegant, minimalist showpiece. Its rarity and consistently high price make it a collector's fish, but in care terms it is a fairly typical sailfin tang.

A large, active grazer, it needs room to swim and graze, and like its relatives it can be assertive toward other tangs.

Natural Habitat & Origin

Zebrasoma rostratum is found in the central Pacific Ocean, ranging from Tuvalu east to Pitcairn — including all of French Polynesia — north to the Line Islands and south to Rapa Iti. It is uncommon throughout this range, living on lagoon and seaward reefs where it grazes algae from rock and coral surfaces.

In the aquarium it wants the same: 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 oxygenation. Reaching up to about 21 cm (8.3 inches), this active sailfin tang needs a large tank — on the order of 450 litres (around 120 US gallons) or more — for swimming and grazing.

Given its rarity and value, a careful quarantine and a mature, stable system are well worth the effort.

Diet & Feeding

The Black 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 nature, and good algae growth on mature live rock provides valuable grazing between meals.

Behavior & Temperament

Like other Zebrasoma, the Black Tang is semi-aggressive and territorial, particularly toward other tangs and especially other sailfin 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

Zebrasoma rostratum is a pelagic spawner with planktonic larvae and is not bred in the home aquarium. Combined with its scarcity, this means all trade specimens are wild-collected and uncommon.

Common Health Issues

Like other surgeonfish, the Black Tang is prone to marine ich (Cryptocaryon irritans) and marine velvet (Amyloodinium ocellatum), especially when stressed by capture and shipping. A thorough quarantine and a stable, oxygen-rich, low-stress environment are essential — all the more so given the fish's value. Provide pristine water, strong flow and a varied herbivorous diet, and this striking black tang can be a remarkable centrepiece for an experienced reefkeeper.