Anchor coral

Widely distributed on coral reefs of the Indian Ocean, central and western Pacific Ocean. In Japan, from Tateyama in Chiba Prefecture southwards. Found in small numbers on reef slopes and channels at depths of 5 to 10 meters. At first glance, it does not look like a coral. Its colony is hemispherical and clings to rocks with anchor shaped tentacles covering its surface. The corals are greenish-gray and brown, along with various shapes of tentacles. Thick skeletal valleys appear when its polyps are dented.