Not furry either, still lovely.
Hammer Coral
Fimbriaphyllia ancora (Veron & Pichon, 1980)
Also called Anchor coral, Sausage coral, Ridge coral, Bubble honeycomb coral, Euphyllia ancora
From Tropical Indo-West Pacific, from the Maldives to the Solomon Islands, with large populations in Indonesia.1
At a glance the quick version
Wild colonies usually reach about 1 m across and sometimes several metres; aquarium pieces are sold at about 4-17 cm.
Looks how to spot one
Large-polyp stony coral (LPS)
A stony coral whose thin-walled skeleton grows in walls or branches, covered by plump tube-like tentacles with T-shaped or anchor-shaped tips. The tentacles stay out day and night.12
Personality what they are like
A sessile coral that is beautiful but assertive: at night it sends out long sweeper tentacles that sting nearby corals, so it is rated aggressive.2
Daily activity how busy a day looks
Sessile; tentacles move gently in the current, and sweeper tentacles reach out up to about 15 cm at night.2
Grooming and care the hands-on bits
Moderate care. Keep calcium, strontium and trace elements topped up, and leave plenty of space around it.2
Home where they are happiest
A reef aquarium with moderate light and medium flow, placed near the bottom with clear space around it. Stable reef-aquarium water: about 22-26 C (72-78 F), pH 8.1-8.4, alkalinity 8-12 dKH, specific gravity 1.023-1.025.2
Food basics what goes in the bowl
Gets much of its energy from symbiotic algae and benefits from a weekly feed of micro-plankton or brine shrimp.12
Company who they like around
A colonial coral that does best with its own patch of rock away from other corals.2
The story where it all began
Veron and Pichon described the hammer coral in 1980 as Euphyllia ancora. A 2017 genetic study moved it, along with the frogspawn coral, into the genus Fimbriaphyllia, though the old name is still common in the hobby.13
Fun facts for the dinner table
- 1
Wild colonies can grow to around a metre wide and occasionally several metres.1
- 2
Hammer corals spawn together in late spring, timed with the moon, on set nights after the full moon.1
- 3
A broken-off tentacle tip can grow into a new colony.1
- 4
Scientists found yolk proteins in this coral that had not been seen in any other cnidarian before.1
- 5
At night its sweeper tentacles can stretch to about 15 cm.2
Recognised by the official bits
- WoRMS
- Fimbriaphyllia ancora (Veron & Pichon, 1980) is the accepted name.4
- Taxonomy (via Wikipedia)
- Described as Euphyllia ancora by Veron & Pichon in 1980; moved to the resurrected genus Fimbriaphyllia in 2017 after a molecular study by Luzon et al.3
- IUCN Red List (via Wikipedia)
- Listed as Vulnerable (2008).1
The care rhythm a typical week and year
A typical home-care rhythm for a Hammer Coral. A starting point, not a vet's advice.
- 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
Owner questions the things everyone asks
How often should I feed my Hammer Coral?
Your Hammer Coral gets most of its energy from the symbiotic algae living inside it, but it benefits from a weekly feed of micro-plankton or brine shrimp. Furry Diary's starting plan suggests feeding depends on the species, so check your coral's response and adjust as needed.12 Pet Wiki plan
What does a Hammer Coral eat, and what should it never eat?
It eats micro-plankton or brine shrimp offered weekly, and also gets energy from its symbiotic algae. What it should never eat isn't specified here, so ask your exotic-pet vet or a good reef aquarium breeder for safe feeding guidelines.12
How much space does a Hammer Coral need?
Give your Hammer Coral its own patch of rock with plenty of clear space around it, because at night it sends out stinging sweeper tentacles up to about 15 cm. A reef aquarium with moderate light and medium flow near the bottom works well.2
What temperature, light or water does a Hammer Coral need?
Keep stable reef-aquarium water at 22-26°C (72-78°F), pH 8.1-8.4, alkalinity 8-12 dKH, and specific gravity 1.023-1.025. Provide moderate light and medium water flow, placing the coral near the bottom.2
How often should I clean a Hammer Coral's home?
Furry Diary's starting plan suggests a 10-20% water change every 14 days, daily top-ups with fresh RO water, and weekly salinity and water tests. Also check the light monthly. Avoid direct cleaning of the coral itself. Pet Wiki plan
Can a Hammer Coral live with others?
It is an assertive coral that sends out long stinging sweeper tentacles at night, so it is rated aggressive toward other corals. It does best with its own patch of rock away from other corals in the tank.2
How long does a Hammer Coral live?
Lifespan varies widely depending on care and environment. For a reliable estimate, ask your exotic-pet vet or a good reef aquarium breeder who knows your specific coral.
Can I handle a Hammer Coral?
Handling is not recommended because its tentacles can sting and the coral is delicate. It is a sessile animal that should stay in place; if you must move it, use gloves and ask a reef expert for guidance.2
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.
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Every fact on this page has a numbered source. Spotted an error? support@petwiki.app.
- Euphyllia ancora (Wikipedia) en.wikipedia.orgused for names, range, size, appearance, reproduction, conservation, fun facts
- Hammer Coral (LiveAquaria care sheet) liveaquaria.comused for care, light, flow, placement, water values, sizes, colours, feeding, sweeper tentacles
- Euphyllia (Wikipedia) en.wikipedia.orgused for 2017 move to Fimbriaphyllia
- WoRMS taxon search: Fimbriaphyllia ancora marinespecies.orgused for accepted name
Checked 2026-09-30. Text is written in our own words from these sources.