Flat Coral
Cycloseris explanulata
A free-living solitary coral that sits loose on sandy reef floors.
About
Flat coral (Cycloseris explanulata) is a solitary, free-living stony coral found across the Indo-Pacific, ranging from shallow reef edges down to around 40 meters. Unlike branching or encrusting reef-builders that anchor firmly to rock, this species simply rests unattached on sandy or rubble substrates, which is one of its more unusual traits. It forms a single, disc-shaped corallite with a relatively flat profile, hence the common name, and a radiating septa pattern that gives it a clean, geometric appearance. In the aquarium, that free-living habit means placement is straightforward: set it on a sandy bed or gently sloped surface and it will sit in place without needing to be glued or wedged. It asks for moderate lighting and lower flow, which makes it a reasonable choice for reef keepers who are still building experience with stony corals. It does not need the intense current that many SPS corals demand, and its light requirements are not especially demanding either. The main thing to keep in mind is that it is a single polyp, so what you see is what you get. There is no colony growth to watch spread across rockwork. Feed it small meaty foods occasionally and it tends to do well.
Similar species
Other coral you might consider
Good tank mates
Species that tend to coexist peacefully with Flat Coral
From the same region
Share the same natural habitat. Great for a biotope-themed tank
Frequently asked questions
- What water parameters does the Flat Coral need?
- The Flat Coral does best with a temperature of 72–82°F, a pH of 8–8.4.
- Is the Flat Coral reef safe?
- The Flat Coral is generally considered reef safe.