A radiole is the “crown” of the Feather Duster, which is usually fan shaped. Often the radioles are brown, tan or orange and banded. The radioles are used to gather floating zooplankton and phytoplankton that it uses for food. It is protected by a tube that it can retreat inside when it is disturbed.
Feather Dusters are native to the reefs of the Indo-Pacific and around Hawaii.