Symphyllia Radians Care Guide
Symphyllia Radians (Symphyllia radians) is a LPS coral. Care covers 75-175 PAR, medium flow, reef parameters and feeding; intermediate level.
Compiled by Aquairi from published sources · Published · Updated
Overview
Symphyllia Radians (Symphyllia radians) is a LPS coral in the family Lobophylliidae. Symphyllia with radiating valleys outward from center. Often deep red, green, or bicolor.
Taxonomy
- Family: Lobophylliidae
- Genus: Symphyllia
- Scientific name: Symphyllia radians
- Common synonyms: Closed Brain Radians
Habitat
In the wild, Symphyllia radians is reported from Indo-Pacific, where it occupies mid to lower reef slopes and lagoons (typically 5-30 m). The species adopts a massive growth form on hard substrate within zooxanthellate reef communities.
Tank requirements
- Salinity (specific gravity): 1.024-1.026
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Carbonate hardness (dKH): 8-11
- Calcium: 400-450 ppm
- Magnesium: 1280-1350 ppm
- Phosphate (max): 0.03 ppm
- Nitrate (max): 5 ppm
- Minimum system age: 3 months
Placement and lighting
- PAR (placement zone): 75-175 PAR
- Water flow: medium
Mount this LPS coral on the lower or mid rockwork or on the sand bed (for free-living forms) where light is moderate. Strong direct flow can damage the fleshy tissue; aim for indirect, varied movement.
Feeding
Symphyllia radians hosts symbiotic zooxanthellae and derives most of its energy through photosynthesis. Supplemental target feeding accelerates growth and supports colouration; commonly accepted items include mysis, reef-roids. Feed once or twice per week after lights-out, when polyps are extended.
Compatibility
This coral is moderately aggressive toward neighbours. It extends sweeper tentacles capable of stinging adjacent corals, so leave generous spacing (10-20 cm) between colonies. Reef-safe with most fish and invertebrates.
Care notes
Difficulty level: intermediate. Reported skeletal growth in well-tuned reef tanks is approximately 0.1-0.3 cm/month. Propagation by fragmentation is straightforward for massive colonies — separate branches or polyps with a bone cutter, glue to plug, allow 1-2 weeks for healing. Maintain stable alkalinity (avoid swings above ±0.5 dKH per day) to preserve tissue health.
Symphyllia radians Propagation Guide
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.