Convict Tang (Acanthurus triostegus) Breeding Guide

Acanthurus triostegus is a pelagic broadcast spawner that gathers in spawning aggregations; with long-drifting acronurus larvae, home breeding is not feasible.

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.