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    Soft coral (encrusting mat)

    Green star polyps

    Briareum (Pachyclavularia) spp.

    Also sold as GSP, Starburst polyps

    Green star polyps (Briareum)
    Photo: Haplochromis, CC BY-SA 3.0, via Wikimedia Commons
    Type
    Soft coral (encrusting mat)
    Care level
    Beginner (invasive)
    Light
    75 to 200 PAR (medium)
    Flow
    Medium
    With neighbours
    Spreads or stings mildly

    Safety: handling green star polyps

    Low hazard. Removal by scraping is hard work typical, check

    How do you care for green star polyps?

    Placement

    Its own rock island; never on the main rockwork if you want it controllable typical, check

    Flow

    Moderate to strong

    Feeding

    Not needed

    Growth

    Fast; mats over rock, glass and neighbours typical, check

    Water quality

    Hardy

    How much light does it need?

    Sources put it at about 75 to 200 PAR, measured where the coral sits. No figure was published for this coral itself, so this is the usual range for its group. Start a new coral at the low end and raise it over weeks.

    Moderate to high light. typical, check

    Which neighbours are safe?

    Overgrowth, not sting

    Isolate on a separate rock

    Fish

    Fish known to nip this group of corals, or small enough to be caught by it.

    Take care (4)

    • Coral beautyCoral beauty may nip soft corals, more so when underfed.
    • Flame angelfishFlame angelfish may nip soft corals, more so when underfed.
    • Foxface rabbitfishFoxface rabbitfish may nip soft corals, more so when underfed.
    • Moorish idolMoorish idol may nip soft corals, more so when underfed.

    Other corals

    Corals that can harm this one if placed too close.

    Take care (10)

    • Hammer coralHammer coral stings neighbours up to about 15 cm away at night; keep the green star polyps out of reach.
    • Frogspawn coralFrogspawn coral stings neighbours; keep the green star polyps out of reach.
    • Torch coralTorch coral stings neighbours; keep the green star polyps out of reach.
    • GalaxeaGalaxea stings neighbours up to about 15 cm away at night; keep the green star polyps out of reach.
    • Horn coralHorn coral stings neighbours; keep the green star polyps out of reach.
    • Fire coral (not Acropora millepora)Fire coral (not Acropora millepora) stings neighbours; keep the green star polyps out of reach.
    • Bubble tip anemoneBubble tip anemone stings neighbours; keep the green star polyps out of reach.
    • Mini maxiMini maxi stings neighbours; keep the green star polyps out of reach.
    • Carpet anemones (Haddon's, giant)Carpet anemones (Haddon's, giant) stings neighbours; keep the green star polyps out of reach.
    • Ritteri anemoneRitteri anemone stings neighbours; keep the green star polyps out of reach.

    Invertebrates

    Invertebrates that may nip corals when hungry.

    Take care (3)

    These checks follow the reasons fish and invertebrates clash: same species or genus, similar shape, mouth size, temperament, food, burrows, tank size and the order they are added. Individual animals differ; every source agrees on that.

    Pests, dips and quarantine

    Few

    General dip

    No dip reliably kills pest eggs, so a dip lowers the risk rather than removing it. Inspect new frags with a torch after lights out, including the underside and the plug.

    Sources

    1. Reef Chasers GSP guideRead 21 October 2026, search summary only.
    2. Nano-Reef GSP removalRead 21 October 2026, search summary only.

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    Zoanthids

    Zoanthus spp.

    Care
    Beginner
    Light
    Low
    Flow
    Medium
    Neighbours
    Spreads or stings mildly

    Photo Kazvorpal, CC BY-SA 3.0

    Palythoa

    Palythoa spp.

    Care
    Beginner
    Light
    Low
    Flow
    Medium
    Neighbours
    Spreads or stings mildly

    Photo Nick Hobgood, CC BY-SA 3.0

    Mushroom coral

    Discosoma spp. (corallimorph)

    Care
    Beginner
    Light
    Low
    Flow
    Low
    Neighbours
    Peaceful

    Photo Kevmin, CC BY-SA 3.0

    Hairy mushroom

    Rhodactis spp.

    Care
    Beginner
    Light
    Low
    Flow
    Low
    Neighbours
    Spreads or stings mildly

    Photo Haplochromis, Public domain