Each individual polyp is a mere few millimeters in diameter and has an opening at its crest that is surrounded by tentacles containing cnidocytes, or stinging cells, that secrete a poison that helps them trap plankton for ingestion.
單一的珊瑚蟲直徑只有幾公釐，身體的頂端有一個開口，開口周圍環繞著一圈觸手，觸手上有許多刺絲包，可以分泌毒液來捕捉水中的浮游生物。