Symphyllia radians Propagation Guide
Propagating the closed brain coral Symphyllia radians, now placed in Lobophyllia: cutting the colony along its radiating valleys with a band saw so each frag keeps polyps and skeleton.
Overview
Symphyllia radians is a closed brain coral in the family Lobophylliidae, whose valleys radiate outward from the centre of the colony. Reef Builders notes the genus Symphyllia was reclassified into Lobophyllia in 2016, though the older name continues in trade; the record name is kept verbatim here. Reef Builders describes Symphyllia as one solid skeleton with puffy tissue and thick walls, the polyp mouths sitting at the centre of the valleys.
Reproductive Mode
Symphyllia radians is colonial rather than solitary, forming a single connected skeleton whose corallites share walls, with polyps lining the radiating valleys. Because the tissue and skeleton make one continuous sheet, the colony can be divided into pieces that each carry living polyps, allowing both asexual fragging in captivity and sexual spawning in the wild.
Fragging / Asexual Propagation
Reef Builders states most LPS corals need a band saw for fragging. On this radiating closed brain coral the cut is run along the valleys between the walls, taking wedge-shaped sections that each include polyps with their skeleton. A coolant of home-tank water tinted light amber with iodine disinfects the cuts, after which each section is dried and glued to a flat-based plug.
Conditions for Propagation
Reef Builders reports that after gently basting off mucus, polyps extend within hours and cut edges expand within days. Stable parameters, gentle flow and clean water support healing, while the heavy mucus typical of brain corals should be allowed to clear so it does not smother neighbours during the recovery period.
Sexual Reproduction
As a zooxanthellate stony coral in the Lobophylliidae, Symphyllia radians reproduces sexually by broadcasting gametes into the water column, where fertilisation produces planula larvae that disperse, settle and grow into new colonies. This pathway, distinct from fragmentation, is how the species renews populations on the reef.
Common Challenges
Because the polyps sit inside the radiating valleys, Reef Builders warns that cutting there can damage them, so the blade must stay centred between the walls. The thick tissue tears if the saw strays, and the coral is moderately aggressive with abundant mucus, so frags need spacing while they heal. Poor water quality slows recovery and promotes tissue recession at the cut edges.