Definition
A sertularian refers to an organism belonging to the Sertulariidae family, which are hydrozoans characterized by their feathery, branching colonies. These colonies consist of individual polyps, each residing within a protective cup called a hydrotheca. Sertularians are commonly found attached to rocks, seaweed, and other submerged surfaces in marine environments. They filter-feed on plankton and other small particles. Imagine tiny underwater forests.