Black Sun Coral Care Guide
Black Sun Coral (Tubastraea micranthus) is a NON-PHOTOSYNTHETIC coral. Care covers 0-50 PAR, medium-high flow, reef parameters and feeding; expert level.
Compiled by Aquairi from published sources · Published · Updated
Overview
Black Sun Coral (Tubastraea micranthus) is a NON-PHOTOSYNTHETIC coral in the family Dendrophylliidae. Tree-like black NPS coral with green polyps. Among the most challenging Tubastraea species.
Taxonomy
- Family: Dendrophylliidae
- Genus: Tubastraea
- Scientific name: Tubastraea micranthus
- Common synonyms: Branching Black Sun Coral
Habitat
In the wild, Tubastraea micranthus is reported from Indo-Pacific, where it grows in shaded, current-swept habitats such as cave walls, overhangs, ledges, and deeper or turbid zones rather than on sunlit reef flats. As an azooxanthellate (non-photosynthetic) species it carries no symbiotic algae and depends on plankton carried by the current. It forms a tree-like colony on hard substrate.
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): 0.1 ppm
- Nitrate (max): 15 ppm
- Minimum system age: 1 year
Placement and lighting
- PAR (placement zone): 0-50 PAR
- Water flow: medium-high
Because this coral does not rely on light, place it where feeding each polyp is practical — shaded overhangs, the underside of rock, or a low, accessible ledge. Moderate, varied flow keeps detritus from settling on the polyps but should not be so strong that it blows food away before capture. Bright light offers no benefit and can encourage nuisance algae to overgrow the skeleton between polyps.
Feeding
Tubastraea micranthus is a non-photosynthetic coral: it does not host symbiotic zooxanthellae and obtains all of its energy from captured food rather than light. Each polyp must be target-fed individually with items such as mysis, reef-roids, amino-acids. Feeding is required several times per week — for many keepers daily — once the polyps have fully extended their tentacles, usually after lights-out or in response to food in the water. Skipping feedings leads to gradual tissue recession and loss of polyps.
Compatibility
This coral is passive 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: expert. Reported skeletal growth in well-tuned reef tanks is approximately 0.1-0.3 cm/month. Propagation by fragmentation is straightforward for tree-like 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.
Propagating Tubastraea micranthus (Black Sun Coral)
Overview
Tubastraea micranthus, the black sun coral, grows and branches into bush- or tree-like colonies and is characteristically dark, often dark green. Its polyps expand up to 3 cm at night to capture prey. Colonies can be large: Philippine specimens reach 1 m tall with 15 cm bases, while Red Sea colonies top out around 44 cm. It is native from the Red Sea to Madagascar and into the Pacific to Fiji.
Reproductive Mode
Being azooxanthellate, the coral relies entirely on capturing planktonic organisms at night and grows at roughly 4 cm per year. It is presumed to reproduce both sexually and asexually, based on its similarity to related Tubastraea species.
Fragging / Asexual Propagation
As with other Tubastraea, propagation works through asexual division of the branching colony. Sections or daughter polyps from the tree-like growth are separated and remounted, with each new piece needing its own feeding to establish.
- Let the tree-like colony branch and add polyps.
- Separate a branch section or daughter polyps.
- Mount each piece onto rubble or a plug.
- Provide good flow and night feeding for each frag.
Feeding & Conditions for Propagation
Its primary diet is planktonic organisms captured at night, and it has been observed taking larger prey such as jellyfish. Unusually for an azooxanthellate coral it is reef-building and remains standing in high-energy environments, so frags benefit from strong flow alongside heavy feeding.
Common Challenges
Slow growth (about 4 cm per year) and a strict feeding requirement make this one of the harder Tubastraea to build up from frags. The heavy feeding needed also loads the system with nutrients that must be exported, and any escaped material poses an invasive risk.