Button Coral

About

Found on shallow to mid-depth reef slopes across the Indo-West Pacific, Cynarina macassarensis is a large-polyp stony coral native to a range stretching from Sumatra east through the Maluku Islands, north into the Philippines, and south to East Timor. It is a close relative of the well-known button coral, and like its cousins it grows as a single, fleshy polyp that can inflate dramatically with water, taking on a puffy, almost balloon-like appearance during the day. The tissue is typically translucent to semi-opaque, often showing rich colors in shades of red, brown, green, or grey depending on the individual and lighting conditions. In the wild it is sessile and tends to occupy sheltered spots where current is gentle and light is moderate rather than intense. That same preference translates well to captive care. This coral does poorly when blasted with strong flow, which can prevent it from fully expanding and feeding. It captures passing zooplankton and benefits from occasional target feeding in the aquarium. Despite being a large-polyp stony coral, it is considered a forgiving choice for newer reef keepers, provided flow is kept gentle and it is given enough space that neighboring corals cannot make contact with its extended tissue.