<i>Minabea aldersladei</i> (Syn. <i>Paraminabea aldersladei</i>) (Leather coral). This coral looks like an upside down carrot growing out of the substrate.  Its striking white polyps are extended only at night to feed.
<a href="//commons.wikimedia.org/wiki/User:Nhobgood" title="User:Nhobgood">Nhobgood</a> Nick Hobgood
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>