Hammer Coral
Euphyllia ancora
Also known as: hammer-tooth coral
Beautiful LPS coral that throws out aggressive sweeper tentacles after dark.
About
Hammer coral (Euphyllia ancora) is one of the more recognizable large-polyp stony corals in the hobby, named for the distinctive T- or anchor-shaped tips on its fleshy tentacles that give it an almost cartoonish, bobbing appearance when flow is right. In the wild it ranges broadly across the Indo-West Pacific, from Japan down through Australia and across to the Maldives, where it grows on reef slopes and lagoon walls anywhere from the shallows down to around 40 meters. Under aquarium lighting the polyps extend into generous, swaying columns that can be tan, green, or gold, often with contrasting tips. What catches a lot of newcomers off guard is what happens after lights out: hammer coral extends much longer, threadlike sweeper tentacles that carry a serious sting and will damage any neighbor within reach. Placement matters a lot with this one. Give it enough room so those nighttime tentacles cannot touch adjacent corals. It is photosynthetic and benefits from moderate, indirect flow rather than a direct powerhead blast. Keepers with some reef experience will find it fairly rewarding, but beginners should get comfortable with stable water quality before adding one to the tank.
Similar species
Other coral you might consider
Good tank mates
Species that tend to coexist peacefully with Hammer Coral
From the same region
Share the same natural habitat. Great for a biotope-themed tank
Frequently asked questions
- What water parameters does the Hammer Coral need?
- The Hammer Coral does best with a temperature of 72–79°F, a pH of 8–8.4.
- Is the Hammer Coral reef safe?
- The Hammer Coral is generally considered reef safe.