Convict Tang (Acanthurus triostegus) Care Guide
A distinctive tang with a pale body and six bold vertical black bars resembling a prisoner's uniform. One of the more peaceful tangs, often found in large schools on reef flats.
Compiled by Aquairi from published sources · Published · Updated
Overview
Acanthurus triostegus is a species in the family Acanthuridae. A distinctive tang with a pale body and six bold vertical black bars resembling a prisoner's uniform. One of the more peaceful tangs, often found in large schools on reef flats. Requires ample swimming space and constant grazing opportunities.
Taxonomy
- Family: Acanthuridae
- Genus: Acanthurus
- Scientific name: Acanthurus triostegus
- Other names: Convict Surgeonfish
- Origin: Indo-Pacific
Habitat
One of the most widely distributed reef fish on Earth, occurring across the Indo-Pacific from East Africa to the Hawaiian, Easter and Galápagos Islands and the eastern Pacific coast. Forms large feeding aggregations on shallow reef flats where it grazes filamentous algae and turf.
Tank requirements
- Minimum tank volume: 400 L
- Temperature: 24-27 °C
- pH: 8.1-8.4
- GH: 8-12 °dGH
- Water flow: strong
- Adult size: 20-27 cm
- Lifespan: 8-15 years
- Recommended group size: ≥ 3
- Difficulty: intermediate
Diet
Classified as herbivore. Recommended feeding frequency: 2x daily. In captivity, offer a varied diet appropriate to the species — quality prepared foods supplemented with frozen or live items of suitable size.
Compatibility
- Temperament: peaceful
- Swimming level: middle
- Compatible tank mates: Clownfish, Wrasses, Angelfish
- Avoid with: Other Acanthurus Tangs
Reef compatibility
Generally classified as reef-safe: does not feed on stony or soft corals, tridacnid clams or ornamental shrimps under normal conditions.
Breeding
- Breeding strategy: egg-scatterer
- Breeding difficulty: advanced
Convict Tang (Acanthurus triostegus) Breeding Guide
Overview
The convict tang, Acanthurus triostegus, is an Indo-Pacific surgeonfish of the family Acanthuridae, often found in large schools on reef flats. Like other surgeonfishes it reproduces by pelagic broadcast spawning into open water, producing planktonic eggs and larvae. For this reason it is not bred in home aquaria.
Spawning Behavior & Trigger
Males and females gather in aggregations to spawn, releasing gametes into the water column for external fertilisation. As in surgeonfishes generally, spawning tends to occur at dusk and is often tied to lunar cycles. These open-water aggregations and ascents cannot be recreated in an aquarium.
Egg & Fry Care
Fertilised eggs are pelagic and develop into the transparent, open-ocean acronurus larva characteristic of tangs, which drifts in the plankton for an extended period before settling on a reef. The acronurus is fragile, sensitive to water quality and dependent on specialised micro-prey, so it cannot be reared under ordinary aquarium conditions.
Common Challenges
Surgeonfish aquaculture has been achieved only at research scale; the first acanthurid bred in captivity was the yellow tang (Zebrasoma flavescens) by the Oceanic Institute in 2015 after about a decade of work with cultured copepod prey. No comparable home-aquarium method exists for the convict tang.