All fish / Acanthuridae

Chocolate Surgeonfish

Acanthurus pyroferus

Also known as chocolate tang, mimic tang, mimic surgeonfish, pyroferus tang, half moon tang, orange gill surgeonfish, yellow-tail mimic tang, モンツキハギ, 火红刺尾鱼, 巧克力倒吊

Adults are a chocolate brown tang with an orange patch behind the gill cover and a yellow-edged, crescent-shaped tail. Juveniles copy the look of yellow or lemon-coloured dwarf angelfish such as the Lemonpeel, which makes them a favourite with hobbyists who like unusual behaviour. It is a hardy algae grazer that helps keep rockwork tidy in reef tanks.

Care at a glance

Care level

Moderate

Temperament

Semi

Adult size

20 cm

Temperature

24 to 28 °C

pH

8.1 to 8.4

Smallest tank

500 litres

Keep as

Keep singly unless the tank is very large

Diet

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

Swims

Middle of the tank

Lifespan

10 to 20 years

Water

Marine (saltwater)

Wild range

Indo-West Pacific, from the Seychelles and East Africa to French Polynesia, north to southern Japan and south to Australia

Breeding

It spawns in open water in the wild, releasing tiny eggs that drift as plankton. There are no reliable reports of captive breeding in home aquariums.

Good to know

Like all surgeonfish, it has a sharp scalpel-like spine at the base of the tail, so handle it with care, and it may fight other tangs, particularly those with a similar body shape. Juveniles look very different from adults and can be mistaken for dwarf angelfish when buying.