Leathery sea anemone

Distributed across the Indo-Pacific. In Japan, from Shikoku southwards. Clings to coral reef slopes and bedrock in water channels. The diameter of an open oral disc can measure 50 cm. Its tentacles are long, and fish such as the yellowtail clownfish and pink anemonefish live in symbiosis with the anemone. There are males and females of this species (dioecism).