Sarcophyton ehrenbergi: Fragging and Propagation
How toadstool leather corals of the genus Sarcophyton are propagated in the reef aquarium by cutting the capitulum margin and reattaching frags, plus notes on their natural sexual reproduction.
Overview
Sarcophyton ehrenbergi is a toadstool leather coral in the family Alcyoniidae (order Octocorallia), recognised by a fleshy stalk topped by a mushroom-shaped crown known as the capitulum. As an octocoral its polyps each carry eight tentacles, and the genus shows dimorphic polyps: larger feeding autozooids that extend from the cap and very small polyps embedded in the surface. Like its relatives it hosts symbiotic zooxanthellae and is largely photosynthetic.
Reproductive Mode
In aquaria these leathers are increased almost exclusively by asexual means. The coral readily regenerates from cuttings, and pieces taken from the capitulum margin will grow into complete new colonies. Sexual reproduction by spawning occurs in the wild but is not a practical home method.
Fragging / Asexual Propagation
A clean, sharp blade is used to trim a section from the edge of the capitulum; the cut piece is then secured to a plug or onto rubble. Because the slimy soft tissue resists glue, frags are commonly held with a rubber band, mesh or onion bag, or simply laid on rubble in low flow until they attach naturally. Many propagators dip the cuttings in iodine followed by clean seawater to reduce infection and rinse slime.
Conditions for Propagation
- Lighting: 75-200 PAR (medium)
- Flow: moderate, increasing once the frag has anchored
- Temperature: 24-26 C
- Mature tank: at least about 3 months old
- Siphon or net out shed mucus, which can irritate neighbouring corals
Sexual Reproduction
On the reef, gonochoric octocoral colonies release eggs or sperm into the water during broadcast spawning; fertilised eggs develop into free-swimming planula larvae that drift before settling and budding into new colonies. This pathway is documented in nature but is not used for home propagation.
Common Challenges
After cutting, the coral often retracts its polyps and develops a shiny waxy film over the surface; this cuticle is normal and is usually sloughed within a few days, after which the polyps re-emerge. Sarcophyton produces defensive terpenes such as sarcophytoxide that act as an antifeedant and can suppress nearby corals, so the slime released during fragging should be removed from the system.