Green Hydnophora

The Green Hydnophora (Hydnophora rigida / Hydnophora pilosa), commonly known as the Horn Coral or Green Velvet Coral, is a notoriously aggressive, radioactive Small Polyp Stony (SPS) coral famous for its distinct, spiky skeletal texture and brilliant glow. Famous for having one of the most potent stings in the entire reef hobby, this species features a vibrant electric lime-to-emerald green coenosteum covered in cone-like skeletal mounds (monticules) that give its branching or encrusting structure a fuzzy, pine-tree aesthetic.

Coloration: Electric neon-green, radioactive chartreuse, or emerald base tissue, accented by fine translucent polyps extending from its sharp skeletal monticules.

Growth Pattern: Branching / Encrusting (forms a thick encrusting base pad before sending up rigid, horn-like vertical branches and irregular antlers). Sold as a frag on a 0.5 – 1 inch frag plug.

Lighting: Moderate to High (PAR 175–300).

Water Flow: Moderate to High (Strong, randomized multi-directional current to keep its dense spiky branches clear of detritus).

Feeding: Extremely active predatory feeder; extends micro-tentacles continuously to capture mysis shrimp, rotifers, liquid amino acids, and particulate coral feeds.

Aggressiveness: Highly Aggressive / Extremely Dangerous to Neighbors (deploys potent mesenterial digestive filaments that can dissolve nearby SPS, LPS, and soft corals on contact).

Care Level: Easy to Moderate (Exceptionally hardy and fast-growing for an SPS, highly resilient against parameter shifts, but requires extreme caution regarding placement).