Platygyra lamellina 'Aussie Rainbow' Maze Brain: Propagation Guide

Propagating the Aussie Rainbow Platygyra maze brain by band-saw division of the massive skeleton, with notes on broadcast spawning and sweeper aggression.

Overview

Platygyra lamellina is a massive stony coral in the family Merulinidae whose colonies usually form rounded mounds, sometimes with nodular swellings, and may also form flat plates. Its long, narrow, meandering corallites with thick walls give the maze-brain appearance, and the septa are neatly arranged, crossing the valley walls. It is distributed across the Indo-Pacific from Madagascar through Indonesia to Japan, on back reef slopes, fore reefs, and in lagoons.

Reproductive Mode

Platygyra lamellina is a simultaneous hermaphrodite that reproduces by broadcast spawning. In the Red Sea it spawns at night during summer on a date set by the moon phase, during the three- to five-day window around the new moon in July and again in August. The 'Aussie Rainbow' is a high-color Australian variety propagated in aquaria by asexual division.

Fragging / Asexual Propagation

Because the skeleton is massive and dense, fully encrusted brain corals are typically cut with a band saw for precision, then the cut pieces are glued to plugs. Each frag should carry several intact valleys with live tissue. After cutting, the exposed skeleton edges are prone to infection, so a coral dip is advisable before mounting.

Sexual Reproduction

After broadcast spawning, fertilized eggs develop into planula larvae that initially lack zooxanthellae. The larvae settle on the seabed roughly two months later and acquire their symbiotic algae at the primary polyp stage. Captive sexual propagation is rarely practiced; division remains the standard hobby method.

Common Challenges

Listed by the IUCN as Near Threatened, this is a slow grower, so fragments take time to re-cover the cut skeleton. Maze brains are sensitive to elevated nutrients, and the cut edges can recede if water quality is unstable during the healing phase.