Green star polyps
Pachyclavularia violacea · also called GSP, Star polyps, Daisy polyps, Briareum violaceum
Green star polyps are a hardy, fast-growing encrusting soft coral prized for the neon-green polyps that emerge from a purple membrane mat. One of the easiest corals for beginners, GSP tolerates a wide range of conditions but spreads aggressively and is best treated as a weed that needs containment.
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Quick facts
| Size | Encrusting mat that spreads indefinitely; individual polyps 3-10 mm across with eight feathery tentacles. |
| Lifespan | 5–50 years |
| Social needs | solo |
| Native region | Indo-Pacific |
| Origin | Old World |
| Climate | 🌴 Tropical |
| Water type | 🌊 Marine |
| Family | Clavulariidae |
| Genus | Pachyclavularia |
Part of the Soft Corals
Soft corals such as leathers, colt, cloves, Anthelia, gorgonians and Sympodium. Non-skeletal octocorals with flexible, often swaying colonies and eight-tentacled polyps; mostly hardy, beginner-friendly reef corals driven by photosynthesis and tolerant of a wide range of light, flow and nutrients.
Habitat & space requirements
From the minimum an animal needs to be kept humanely, up to the ideal setup. Bigger is almost always better — minimums are floors, not targets.
Life & growth stages
How this animal changes through its life — each stage often has its own care, diet and space needs.
Color & pattern variants
Natural variants occur in the wild; selectively bred (man-made) variants were developed in captivity.
representativeNeon green →
The classic bright fluorescent-green polyp form that gives the coral its name, with a contrasting purple base mat.
representativePurple/metallic →
A form with darker, more metallic green-to-bronze polyps and a strongly purple membrane.
representativeStandard Green Star Polyps →
The ubiquitous bright-green-polyped GSP on a purple encrusting mat. Bulletproof and fast-growing — often a beginner's first coral.
Tip: Isolate it on its own rock or an island frag plug — it spreads aggressively over rock, glass, and other corals like a weed.
representativeNeon / Toxic Green GSP →
A higher-fluorescence line with electric neon-green polyps that pop hard under actinic light. Just a brighter pigment form of the standard.
Tip: Run blue-heavy/actinic lighting to maximize the neon glow; under warm white light it looks like ordinary green GSP.
representativeDaisy / Pink-Center GSP →
Green polyps with a contrasting pink, white, or cream center mouth, resembling little daisies. A slightly more decorative form.
Tip: Moderate flow keeps the polyps fully open and showing the centers; in stagnant water the mat collects detritus and polyps stay retracted.
representativePurple/Lavender Polyp GSP →
A less common color form with purplish or lavender-tinged polyps instead of green. Color is light-dependent and can shift.
Tip: Keep light moderate and stable — too much PAR pushes these toward brown/green and you lose the purple tone.
representativeSympodium (Blue Star Polyp lookalike) →
Often sold beside GSP, a blue-green soft-coral mat with feathery polyps and no white center. A calmer-growing alternative to true GSP.
Tip: Slower and less invasive than GSP, but still mount on an isolated rock; give moderate flow to keep the delicate polyps extended.
representativeEncrusting 'Eagle Eye' GSP →
Green polyps with a distinct yellow or orange ringed center eye on a fast purple mat. A more eye-catching pattern form.
Tip: If it ever creeps where you don't want it, peel the mat off the glass/rock by hand — it lifts easily and re-attaches elsewhere.
representativeGreen Star Polyps (Standard) →
A mat-forming soft coral with a purple encrusting base and bright green, eight-tentacled polyps that sway in the flow like a grassy lawn. The classic 'GSP' that nearly every reefer encounters.
Tip: Place on its own isolated rock or island away from the main reef — it spreads aggressively over rock, sand, and even glass, so give it a barrier of bare sand. Tolerates low to high light and any flow.
representativeNeon / Metallic Green Star Polyps →
A brighter, more fluorescent strain of GSP whose polyps glow an intense lime-neon green under blue/actinic light. Visually punchier than the dull standard form.
Tip: Run heavier blue spectrum to pop the green fluorescence; still isolate on a frag-island because it encrusts and overruns neighbors just like the standard form.
representativeNeon Green Star Polyps →
The classic GSP color form: a fast-spreading mat of fluorescent, almost lime-neon green eight-tentacled polyps over a reddish-purple stolon (the 'purple mat'). This is the standard against which other GSP color forms are compared.
Tip: Glue it to its own isolated rock or island away from the main rockwork, since it encrusts aggressively over neighboring corals. It shows the best neon color under moderate light (PAR ~100-150, and it pops further under blue/actinic) with moderate-to-strong flow to keep detritus off the mat.
representativeWhite Center Green Star Polyps →
Green star polyps whose polyp centers carry a contrasting bright white 'flower' eye, giving each eight-tentacled polyp a little daisy-like look against the green tentacles. A widely-grown center-color variation of standard GSP.
Tip: Place it low-to-mid on its own rock under moderate light and moderate-to-high flow; the white center holds best when the mat is kept clean of detritus and water parameters are stable. Like all GSP it will encrust over neighbors, so give it an island.
representativeBlue Eye Green Star Polyps →
A GSP color form where the polyp centers glow blue rather than the usual white or green, giving a 'blue eye' against bright green tentacles. The blue center is the prized trait and is essentially the blue version of a white-center GSP.
Tip: Run heavier blue/actinic light (vendors recommend PAR ~80-150 with a strong 420-470 nm spectrum) to keep the blue center vivid instead of washing out to green or brown. Keep nutrients moderate and isolate it on a dedicated rock so it doesn't overgrow tankmates.
representativeMetallic Center Green Star Polyps →
A GSP with an intensely metallic, iridescent green center that fluoresces brighter than standard neon GSP, fading to a duller green or brown if conditions slip.
Tip: Keep blue/UV-heavy lighting and lower nutrients with strong randomized flow to hold the metallic fluorescence; too much harsh white light and high phosphate will brown it out. Still spreads readily, so keep it on its own rock.
representativeLong Polyp Neon GSP →
A neon green GSP sold under a 'long polyp' label for its flowing eight-tentacled polyps that wave in the current, giving a shaggier, more animated look than tight standard GSP.
Tip: Give it moderate light (the vendor cites ~150-250 PAR) and moderate flow so the polyps sway and fully extend; keep it on its own island rock as it still spreads readily.
representativeToxic Green Star Polyps →
A super-saturated, almost glowing 'toxic' green GSP marketed for its extra-bright, eye-searing green polyps over the typical reddish-purple mat.
Tip: Standard GSP care: own rock, moderate light and moderate-to-high flow; the toxic green saturates best under blue-heavy lighting. Some keepers benefit from light iodide/amino-acid dosing, though it is not required.
representativeWWC Sizzling Star Polyps →
A vendor-branded star polyp with toxic yellow, fuzzy polyps rather than the usual green, used to add a contrasting color to a star-polyp garden. Part of the same star-polyp complex as GSP.
Tip: Treat it like GSP: place it on its own rock under moderate-to-high light and flow; the yellow holds best with clean flow keeping detritus off the mat. It is described as one of the hardiest soft corals.
representativePurple (Branching) Star Polyps →
A close GSP relative with a vivid purple encrusting base and green, often white-centered polyps; some forms grow as upright branching 'fingers' or knobby spires rather than a flat mat.
Tip: Same easy care as GSP - its own rock, moderate light, moderate-to-high flow; the branching forms appreciate a bit more flow to develop their upright structure.