radiole

noun2

1. •
   A heavily ciliated feather-like tentacle occurring in clusters on the crowns of certain tubeworms, especially those of the order Canalipalpata (fan-head worms), used for feeding and respiration.

   • Family Sabellidae [...] Head with a characteristic crown of 2 groups of pinnate projections called radioles [...], which sometimes bear eyes, and project from the tube when the worm is feeding. — 2011
2. •
   The spine of a sea urchin.