The Australian Doughnut Coral (Acanthophyllia deshayesiana) is a large polyp stony coral native to the Indo-Pacific region, including the Great Barrier Reef. It is named for its circular shape and often brightly colored fleshy tissue. The coral has a distinctive appearance due to its large corallites (the skeletal cups that house the polyps) which are separated by pronounced walls. The coral's polyps extend during the day to feed on zooplankton and retract at night. The Australian Doughnut Coral is relatively hardy and can thrive in a range of lighting and flow conditions, making it a popular choice for reef aquaria. However, it can be sensitive to high levels of nitrates and phosphates, and requires calcium and alkalinity supplementation for optimal growth.