"radiole : (zoology) The spine of a sea urchin. (zoology) A heavily ciliated feather-like tentacle..."

“radiole : (zoology) The spine of a sea urchin.
(zoology) A heavily ciliated feather-like tentacle occuring in clusters on the crowns of certain tubeworms, especially those of the order Canalipalpata (the fan-head worms), used for feeding and respiration.”

- https://en.wiktionary.org/wiki/radiole#English

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