Fine, unbranched filaments algae, as benthic small beards
or as floating light-green Algae flocks.
<a href="//commons.wikimedia.org/wiki/User:Teacoolish" title="User:Teacoolish">Th.Voekler</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>