Velvet Horn Coral Care Guide
Velvet Horn Coral (Hydnophora exesa) is a LPS coral. Care covers 100-200 PAR, medium-high flow, reef parameters and feeding; intermediate level.
Compiled by Aquairi from published sources · Published · Updated
Overview
Velvet Horn Coral (Hydnophora exesa) is a LPS coral in the family Merulinidae. LPS with conical projections (monticules) and short tentacles. Highly aggressive — long sweepers harm neighbors.
Taxonomy
- Family: Merulinidae
- Genus: Hydnophora
- Scientific name: Hydnophora exesa
- Common synonyms: Hydnophora, Horn Coral
Habitat
In the wild, Hydnophora exesa is reported from Indo-Pacific, where it occupies mid to lower reef slopes and lagoons (typically 5-30 m). The species adopts a encrusting 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): 100-200 PAR
- Water flow: medium-high
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
Hydnophora exesa hosts symbiotic zooxanthellae and derives most of its energy through photosynthesis. Additional feeding is generally not required when lighting is adequate.
Compatibility
This coral is very-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 0.3-0.7 cm/month. Propagation by fragmentation is straightforward for encrusting 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.
Velvet Horn Coral (Hydnophora exesa) Propagation Guide
Overview
Hydnophora exesa, the velvet or horn coral, is a stony coral in the family Merulinidae found in the oceans of north and east Australia, Southeast Asia, and East Africa. Its surface bears conical projections, called monticules, between short tentacles. Depending on tank conditions it grows as an encrusting form or as a branching one, both of which lend themselves to fragmentation.
Reproductive Mode
In aquaria Hydnophora is propagated asexually by cutting off branches or encrusting sections. Because it spreads across rockwork and branches readily, offending branches or sections can simply be cut off to make frags. It is among the easiest corals to frag and a fast grower that spreads quickly once established.
Fragging / Asexual Propagation
- On branching colonies, select a branch; on encrusting colonies, choose a section growing over rock.
- Cut off the branch or section with coral clippers, or use a saw on thicker pieces.
- Work where the coral has spread so the parent keeps enough tissue to recover.
- Glue or epoxy the frag to a plug.
- Place it in moderate flow and moderate to high light, well away from other corals, to resume growth.
Cutting off sections is also how overgrowth is controlled, since Hydnophora spreads across rockwork and stings whatever it reaches.
Conditions for Propagation
Hydnophora requires moderate flow and moderate to high lighting, with care requirements similar to Euphyllia, and it will grow and spread under the right conditions. Stable temperature near 24-26 degrees Celsius, pH 8.1-8.4, and steady alkalinity, calcium, and magnesium support its fast growth.
Common Challenges
Hydnophora is very aggressive: both branching and plating forms can produce sweeper tentacles over five inches long that kill surrounding corals. Frags must be placed well away from neighbors, and the coral's tendency to spread across rock means it can overgrow and sting anything it contacts.