Propagating Torch Coral (Euphyllia glabrescens)

Fragging guide for torch coral, Euphyllia glabrescens, whose phaceloid branching skeleton lets heads be cut apart, with potent sweeper-tentacle and brown-jelly cautions.

Overview

Torch coral, Euphyllia glabrescens, is a large-polyped stony coral of the family Euphylliidae, named for its long tubular tentacles with knob-like, often bicolored tips. It forms a phaceloid arrangement of corallites about 20-30 millimeters across and occurs across the Indo-Pacific, including Indonesia, Fiji, Australia, Southeast Asia, and southern Japan, at depths of about 1 to 35 meters. It relies on symbiotic zooxanthellae for most of its energy.

Reproductive Mode

The torch coral reproduces sexually in the wild and asexually by colony division. Its phaceloid, branch-like skeleton with discrete corallites makes it relatively easy to frag by separating individual heads, which has contributed to its wide availability in the hobby.

Fragging / Asexual Propagation

Because each torch head sits on its own corallite within a phaceloid skeleton, fragging is done by cutting between heads along the skeleton, generally without cutting through living flesh. Each frag retains a head on its own piece of skeleton, and after dipping and mounting it heals and grows out into a new colony.

1. Use sterile bone cutters or a rotary tool, with gloves and eye protection.
2. Cut between heads along the phaceloid skeleton, keeping skeleton under each head.
3. Avoid cutting into polyp flesh to limit the chance of infection.
4. Dip and mount the frags, then place them in adequate flow to heal.

Conditions for Propagation

Torch frags recover under moderate lighting and moderate flow, with stable alkalinity, calcium, and magnesium and low nutrients. Torch corals are generally slower to settle than hammers or frogspawn, so keep conditions steady and avoid moving freshly mounted frags while their tentacles re-extend.

Sexual Reproduction

Sexual reproduction in Euphyllia is broadcast spawning, with gametes released into the water for external fertilization, typically synchronized to lunar cues. This wild route is not used for aquarium propagation, so torch coral is multiplied in captivity exclusively by fragging.

Common Challenges

Torch corals carry long sweeper tentacles tipped with potent stinging cnidocytes and are among the more aggressive Euphyllia, so frags need wide spacing from other corals. The most serious post-fragging risk is brown jelly disease, which can kill a colony within weeks and spread to neighbors; never frag or place a specimen already showing a brown gel-like coating.