Green Star Polyps

Description

• Scientific Name: Pachyclavularia violacea (sometimes Briareum spp. too)

• Common Name: Green Star Polyp, GSP, Starburst Polyps

• Family: Tubiporidae

• Origin: Indo-Pacific — commonly found in shallow reef areas

• Appearance:

  • Bright neon green or fluorescent green polyps with feathery tentacles and a purple or pinkish mat (called the coenenchyme)

  • Polyps extend during the day and retract at night or when disturbed

  • Grows in a sheet-like mat, encrusting and spreading over surfaces

• Growth Form: Encrusting, can carpet rocks, back walls, frag plugs, and sand

Care Requirements

Lighting

• Moderate to High PAR (100–250)

• Very tolerant—will grow under lower light, but colors pop under blues/actinics

• Can become invasive in high light areas with strong growth

Water Flow

• Moderate to High flow

• Needs flow to keep polyps clean and help with waste removal

• In low flow, it may attract detritus and retract more often

Placement

• Best on isolated rocks or islands to control spread

• Can grow up walls, frag racks, or even across the sand

• Avoid placing it too close to slow-growing corals—it can overtake and smother them

Maintenance & Behavior

• Extremely hardy—a great starter coral

• Can survive in a wide range of parameters, but thrives with stability

• Known to "close up" for days after fragging, moving, or dips—this is normal

• Fragging is super easy: cut or peel a section of the mat and glue it to a new surface

Invasiveness Warning

• GSP can become a nuisance if not controlled

• Keep it separate from your main rockwork if you don’t want it spreading everywhere

• Periodic pruning may be needed to keep it from overtaking other corals

Cool Facts

• Looks like underwater grass waving in the current—super aesthetic

• Some hobbyists use GSP to create living back walls or “coral lawns”

• Polyps retract instantly if touched or disturbed—fun to watch

Pro Tips

• Want a GSP “island”? Mount it on a single rock surrounded by sand so it can’t spread easily

• If it's not opening, check for:

  • Low flow

  • Pest irritation (nudis, crabs)

  • Major parameter swings

• Clean detritus off the mat occasionally to avoid algae buildup