Aussie Scoly (Homophyllia australis) Propagation Guide

How Homophyllia australis (Aussie Scoly) is propagated: why this single-polyp coral resists conventional cutting, the bottom-up skeleton-trimming method, and its sexual spawning.

Overview

The Aussie Scoly is the Australian large-polyp stony coral Homophyllia australis (formerly Scolymia australis), in the family Lobophylliidae. It is a solitary, single-polyp coral that forms a circular fleshy disc, prized for its colors. Because it is a single polyp rather than a colony of separate heads, it cannot be fragged the way branching corals are.

Reproductive Mode

Captive propagation of Homophyllia australis is not as easy as for most corals. As a single-polyp LPS, cutting through it with a coral saw usually ends in its demise, and it rarely if ever forms new polyps at the base of a mature polyp. It can reproduce by splitting, but this is uncommon, so aquarists rely on a specialized trimming method or on sexual spawning.

Fragging / Asexual Propagation

1. Do not cut through the polyp itself; slicing through a single-polyp Scoly with a saw usually kills it.
2. Instead, trim skeleton from underneath the coral, working from the bottom up.
3. Look at the interior valley to judge where to trim, and cut extremely close without exposing or holing the flesh.
4. If a hole is accidentally made it can still regenerate a new Scolymia, but it takes much longer.
5. Grow out the trimmed coral; the underside regrows new flesh and a new polyp over time, and the process can repeat every 3-4 months.

One Australian farm has propagated Scolymia this way for roughly ten years after discovering it while trimming excess bone off the bottom.

Conditions for Propagation

Scolys do best in moderate to lower lighting, since too much light can cause bleaching while too little harms long-term health. Moderate, indirect flow keeps detritus off the flesh without damaging it. Spot feeding meaty foods such as mysis and brine a couple of times a week provides much of the coral's energy and supports regeneration.

Sexual Reproduction

Homophyllia australis is a hermaphroditic broadcast spawner, releasing eggs and sperm into the water during a spawning event, and it has been spawned in captivity. Larval rearing is specialized work rather than a routine hobby technique, but it offers a non-destructive route to new corals that does not risk the parent polyp.

Common Challenges

The main challenge is that this is a single irreplaceable polyp: a failed cut destroys the whole coral. Even successful trimming is slow, and documented attempts to cut the polyp are very risky and rarely regrow into a full, round disc, which is why the bottom-up method is preferred.