Acropora austera Propagation Guide

Propagating Acropora austera, a bushy thin-branched SPS coral, by fragmentation: cutting branch tips, gluing frags to plugs, and providing the stable chemistry, high light and high flow that healing fragments need.

Overview

Acropora austera is a bushy, thin-branched stony coral of the family Acroporidae. It grows as a colony of small polyps that share tissue and build a calcium carbonate framework, while symbiotic Symbiodinium algae in the tissue generate energy through photosynthesis. Its many slender branch tips offer numerous fragging points for SPS propagation.

Reproductive Mode

Acropora reproduce sexually by releasing gametes and asexually when broken branches reattach to form new colonies. Aquarium propagation uses the asexual route, since each fragment is a genetic copy of the parent that continues growing once mounted.

Fragging / Asexual Propagation

Pick a healthy, coloured branch tip from a settled colony.
Cut or snap the thin branch; handle gently as slender branches break easily.
Glue the frag to a plug or rock with cyanoacrylate or epoxy.
Keep the frag at moderate light and flow while the cut heals, then raise it.
Dip and quarantine new frags before adding them to a display.

In a healthy reef tank, small finger-sized fragments can grow into much larger colonies over one to two years, so a single bushy parent provides a steady supply of frags.

Conditions for Propagation

Stable water chemistry is essential. Acropora bleach readily when stressed because they lose their zooxanthellae, so temperature, salinity, alkalinity, calcium and magnesium must be held steady. High light and high flow feed the dense skeletal growth this thin-branched form depends on.

Sexual Reproduction

Wild Acropora take part in annual mass-spawning, broadcasting gametes into the water for external fertilisation. This is rarely reproduced in aquaria, so hobby propagation relies on fragmentation.