Hydnophora sp.
| Care Level | Moderate |
| Lighting | Moderate to high |
| Water Flow | Moderate to strong |
| Placement | Rock, mid tank — with space around it |
| Aggression | Aggressive (stinging / sweeper tentacles) |
| Coloration | Green, cream, brown |
Overview
Hydnophora, the horn or velvet coral, is instantly recognizable for the field of small bumpy cones (hydnophores) that cover its branching or encrusting skeleton, giving it a velvety texture. Bright neon-green forms are especially popular and fluoresce hard under blue light. It is a fast grower and a striking centerpiece, but it comes with a mean streak.
Care & Placement
Moderate and not difficult if its needs are met: give it moderate to high light and moderate to strong flow, and mount it on rock with open space on all sides. The key word is space — Hydnophora is aggressive and will sting and kill any coral it grows into or reaches with its tentacles, so do not place it close to other corals. It grows quickly, so account for where it will be in a few months, not just today.
Feeding
Photosynthetic, drawing most of its energy from light through its zooxanthellae, so it does not require feeding. It will capture small meaty foods and benefits from occasional feedings of finely chopped seafood or a coral food, which can speed growth, but light plus stable water is the foundation.
Propagation
Easy to frag: cut or snap off a branch tip with bone cutters and glue it to a plug or rubble. It heals and grows quickly. Wear gloves and rinse tools — the same tissue that stings other corals can irritate skin.
Cautions
Aggression is the whole story. Hydnophora deploys sweeper tentacles and stings neighboring corals, and because it grows fast it can quickly overrun a section of rock. Give it a wide buffer, watch its growth, and trim it back when it heads toward tankmates. Its rapid encrusting can also overgrow the bases of nearby corals from below.
Frequently Asked Questions
Is Hydnophora aggressive?
Yes — it is one of the more aggressive corals, stinging and killing neighbors it grows into or reaches with its tentacles. Always give it open space on all sides and keep an eye on its fast growth toward tankmates.
Why is my Hydnophora losing color or receding?
Usually light or flow related, or tissue damage from contact with a neighbor. Give it moderate-to-high light, good flow to keep detritus off the branches, stable parameters, and make sure nothing is stinging it back.
Does Hydnophora need to be fed?
No. It is photosynthetic and does fine on light alone, though it will take small meaty foods and occasional feedings can boost its already-fast growth.