About Green Star Polyps
Bright green polyps on a purple encrusting mat — the textbook beginner soft coral. Nearly indestructible and flow-responsive. Will overrun anything it touches, so place on an isolated rock from day one.
Briareum violaceum, commonly called star polyp, is a species of a soft coral in the family Briareidae.
Notes from the editors
What it looks like. Encrusting soft coral with a bright purple-to-brown base mat that develops cream-to-green polyps when extended. Different from green star polyps (Pachyclavularia) despite similar common names — polyps are smaller and more uniform.
In your tank. Behaves identically to GSP: encrusting growth across any surface, polyps responding to flow, peaceful to other corals biologically but smothering them physically. The mat itself is the issue, not the polyps.
Placement and care. Mount on an isolated frag plug or lone rock away from the main aquascape. Tolerant of suboptimal conditions and a good first encrusting coral for a new system. Polyp retraction during the day is normal for new frags; full extension typically returns within a week or two.
Sourcing and feeding. Captive-propagated frags very widely available and inexpensive. Photosynthetic; no target feeding needed.
Care info is a starting point, not a guarantee. Individual specimens, water chemistry, and tankmate dynamics vary. Verify against multiple sources and adjust to what you observe. See our terms & disclaimers.
Related corals
Sources & attribution
- Taxonomy and accepted name from the World Register of Marine Species (WoRMS AphiaID 517640).
- Description content adapted from Wikipedia, available under CC BY-SA 4.0.
- Photo: (c) portioid, some rights reserved (CC BY) · CC-BY (via iNaturalist or Wikimedia Commons).