All fish / Acanthuridae

Lieutenant Tang

Acanthurus tennentii

Also known as lieutenant surgeonfish, doubleband surgeonfish, tennent's surgeonfish, tennenti tang, acanthurus tennenti, lieutenant tang, ハナグロハギ, 坦氏刺尾鱼

A large surgeonfish with a brownish to grey body, a pale blue-edged tail and two dark bands ringing the scalpel spine near the tail base, which is the easiest way to recognise it. Juveniles are more orange-yellow. Keepers value it as a hardy grazer that helps control filamentous algae in big reef or fish-only systems.

Care at a glance

Care level

Moderate

Temperament

Semi

Adult size

25 cm

Temperature

24 to 28 °C

pH

8.1 to 8.4

Smallest tank

700 litres

Keep as

Singly, or with unrelated tangs in a very large tank

Diet

Herbivore: nori, marine algae, spirulina-based flakes and pellets, plus some mysis and brine shrimp

Swims

Middle of the tank

Lifespan

10 to 20 years

Water

Marine (saltwater)

Wild range

Indian Ocean: East Africa, Maldives, Sri Lanka, Chagos to western Indonesia

Breeding

Spawns in groups in open water, releasing tiny pelagic eggs and larvae. It has not been bred in home aquariums and all stock is wild caught.

Good to know

Grows to around 30 cm and needs plenty of swimming space; it can fight with other tangs, especially Acanthurus species of similar shape. The tail spines are sharp, so handle with care.