Northern Star Coral
Astrangia poculata
Also known as: northern cup coral, Northern Star Stony Coral, northern stony coral
A cold-water stony coral that thrives with or without symbiotic algae.
About
Northern star coral (Astrangia poculata) is a genuinely unusual animal in the reef hobby. It's one of the few stony corals native to the temperate Atlantic coast of North America rather than tropical Indo-Pacific reefs. In the wild it grows on rocky shorelines, jetty pilings, and other hard substrates anywhere from the surface down to considerable depth, and it handles a wider temperature range than almost any other coral you're likely to encounter. The colony form can be encrusting, submassive, or branching depending on conditions, and individual corallites are compact, roughly circular, and relatively small at up to about 10 mm across. The walls between corallites are clearly defined, with neatly beaded septa and a well-developed central columella. What really sets this species apart is its flexibility with light: under brighter conditions it hosts zooxanthellae and takes on a brownish tone, while in lower-light situations it goes azooxanthellate and becomes translucent. In the aquarium it's rated intermediate in care, partly because matching its somewhat unusual needs takes a bit of thought. It's considered reef safe and does best under good lighting with moderate water movement.
Similar species
Other coral you might consider
Good tank mates
Species that tend to coexist peacefully with Northern Star Coral
From the same region
Share the same natural habitat. Great for a biotope-themed tank
