Propagating Tubastraea faulkneri (Orange Sun Coral)

Propagating the non-photosynthetic orange sun coral Tubastraea faulkneri: dividing colonies, daughter polyps and the heavy zooplankton feeding required to keep frags alive.

Overview

Tubastraea faulkneri is one of the sun corals, large-polyp stony corals with hard, non-reef-building skeletons. Like the rest of the genus it is azooxanthellate: it lacks symbiotic zooxanthellae and extends long tentacles at night to catch passing zooplankton. Its large polyps let it take relatively large prey.

Reproductive Mode

Tubastraea reproduces both sexually, releasing planula larvae, and asexually. The genus is also known to spread by budding and by forming runners that can extend over 10 cm per year, producing new polyps adjacent to the parent colony.

Fragging / Asexual Propagation

Hobbyist propagation works with this asexual budding. As a colony adds polyps and spreads, daughter polyps or sections of the colony can be separated and remounted, and larvae that settle nearby (typically within about a metre of the parent in the wild) can also be collected and grown on.

• Separate daughter polyps or a section once the colony has spread.
• Mount detached pieces onto rubble or a plug.
• Collect any larvae that settle on nearby surfaces.
• Feed every piece individually until established.

Feeding & Conditions for Propagation

Sun corals accept foods such as frozen mysis shrimp. Feeding every other day is enough for survival, while daily feeding enables faster growth, which matters when building up frags. Each polyp should be target-fed because the coral cannot rely on light at all.

Sexual Reproduction

In the wild Tubastraea produces planula larvae that can survive up to about two weeks and typically settle within a metre of the parent; sexual reproduction has been recorded in spring, summer and winter. Aquarium propagation generally relies on asexual division rather than larval rearing.

Common Challenges

The chief risk is starvation: without consistent target feeding the coral declines, and the heavy feeding needed to grow frags adds nutrients that must be exported. Sun corals are considered relatively easy among non-photosynthetic corals, but only if the feeding regimen is maintained.