Acanthastrea

Acanthastrea, or 'Acan,' is a popular Large Polyp Stony (LPS) coral with large, fleshy, circular polyps that are fused together in a colony. They are famous for their 'designer' color morphs, which can have rainbows of red, green, blue, and orange. They are semi-aggressive but are known for their powerful feeding response. They should be placed in low-to-moderate light and flow. An interesting fact is their 'invisibility' at night; unlike most LPS, they rarely extend sweeper tentacles, but they will extend short 'feeding' tentacles if they smell food in the water.