At a glance the quick version
Looks how to spot one
Encrusting soft coral mat
A thin, rubbery purple mat that spreads over rock, sprouting many small star-shaped green polyps that sway in the current. The polyps glow strongly under blue (actinic) light.21
Personality what they are like
A peaceful coral that opens a field of waving star polyps by day and pulls them in when disturbed.1
Daily activity how busy a day looks
Sessile; spreads quickly over nearby rock and glass.1
Grooming and care the hands-on bits
Easy care. Add iodine and trace elements as part of routine reef care. New colonies are made by cutting pieces from the mat and gluing them to rock; many keepers give it its own rock so it spreads only where wanted.1
Home where they are happiest
A reef aquarium with moderate to high light and medium to strong flow, from the middle to the top of the tank. Stable water around 22-26 C (72-78 F), pH 8.1-8.4, 8-12 dKH, specific gravity 1.020-1.025.1
Food basics what goes in the bowl
Mostly fed by algae living in its tissue; weekly micro-plankton or filter-feeder foods are a useful extra.1
Company who they like around
A colonial coral that is peaceful with tankmates.1
The story where it all began
The species was first described by Quoy and Gaimard in 1833 and was long sold under the name Pachyclavularia violacea. Today it is placed in Briareum, a genus set up by Blainville in 1834, and its fluorescent green polyps made it a classic first coral for reef keepers.32
Fun facts for the dinner table
- 1
The green polyps fluoresce strongly under actinic (blue) aquarium lighting.2
- 2
The popular hobby name Pachyclavularia violacea is now an old synonym of Briareum violaceum.3
- 3
Scientists say the genus still needs a thorough review because many sold specimens look alike.2
- 4
A small cutting glued to rock can start a whole new colony.1
Recognised by the official bits
- WoRMS
- Pachyclavularia violacea Quoy & Gaimard, 1833 is listed as an unaccepted name; the accepted name is Briareum violaceum. Pachyclavularia Roule, 1908 is a synonym of Briareum Blainville, 1834.3
- Taxonomy (via Wikipedia)
- Genus Briareum (family Briareidae), seven species; the genus still needs careful study and hobby specimens are often labelled loosely.2
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Green Star Polyps. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- FeedingDepends on species, many feed from the light and the watervaries
- Salinity checkevery week
- Water testevery week
- Top-upTop up evaporation with fresh RO water, not salt waterevery day
- Water changeAbout 10 to 20% of the waterevery 2 weeks
- Light checkevery month
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at support@furrydiary.app and we will fix it.
- Metallic Green Starburst Polyp, Briareum sp. (LiveAquaria care sheet) liveaquaria.comused for care, light, flow, water values, sizes, colour, feeding, propagation
- Briareum (Wikipedia) en.wikipedia.orgused for genus, fluorescence, taxonomy notes, history
- WoRMS taxon search: Pachyclavularia marinespecies.orgused for accepted name and synonyms
Checked 2026-09-30. Text is written in our own words from these sources.