Green Star Polyps (Briareum violaceum) Care Guide

Briareum violaceum, known as green star polyps or GSP, is a hardy encrusting octocoral with fluorescing star-shaped polyps.

Overview

Briareum violaceum is a soft coral in the family Briareidae, popular in the reef hobby as green star polyps (GSP). It forms a purple encrusting mat from which bright green or purple star-shaped polyps extend, and the polyps fluoresce under actinic light. It is hardy and spreads readily over rock.

Taxonomy

Family: Briareidae
Order: Scleralcyonacea
Class: Octocorallia
Scientific name: Briareum violaceum
Authority: (Quoy & Gaimard, 1833)
Synonym: Pachyclavularia violacea (a common hobby label)

Habitat

It is distributed across the Indo-Pacific, where it encrusts hard substrate on reefs. In the trade many similar-looking specimens are sold under the name Pachyclavularia violacea, which WoRMS treats as a synonym of Briareum violaceum.

Tank requirements

Temperature: 24-26 C (75-79 F)
pH: 8.1-8.4
Carbonate hardness (KH): 8-11 dKH
Calcium: 380-450 ppm
Magnesium: 1280-1350 ppm
Specific gravity: 1.024-1.026
Lighting: ~50-200 PAR (medium)
Flow: medium
Minimum tank maturity: 3 months

Feeding

The coral is photosynthetic, relying on symbiotic zooxanthellae for most of its energy. It absorbs additional dissolved nutrients from the water and does not require target feeding.

Compatibility

It is passive and reef-safe, compatible with fish and shrimp. Because it grows aggressively across rock, it is best placed on isolated rockwork to keep it from overgrowing neighbouring corals.