Sue Daly / Feather duster fan worm (Sabella spallanzanii) with tentacles moving in the current, Sark, British Channel Islands, UK, August.

Alex Mustard,Alex Mustard / A nudibranch (Flabellina nobilis) feeding on a solitary hydroid (Tubularia indivisa), note how the hydroid is bent back as it is pulled into the nudibranch's mouth. Gulen, Bergen, Norway. North East A...

Wild Wonders of Europe / Banfi / Tube worm (Protula tubularia) Larvotto Marine Reserve, Monaco, Mediterranean Sea, July 2009

Wild Wonders of Europe / Banfi / Tube worm (Protula tubularia) Larvotto Marine Reserve, Monaco, Mediterranean Sea, July 2009

Pascal Kobeh / Field of Peacock feather dusters / Spiral tube-worms (Sabella spallanzanii), Canary Islands

Andy Jackson / 2020VISION / Oaten pipe hydroid group (Tubularia indivisa), with Jewel anemones (Corynactis viridis), Muckle Flugga, Shetland, Scotland, UK, June.

Pascal Kobeh / Spiral tube-worm (Sabella spallanzanii), Gozo Island, Malta. Mediterranean Sea.

Alex Mustard / Nudibranch (Flabellina nobilis) feeding on a solitary hydroid (Tubularia indivisa) and laying eggs. Gulen, Bergen, Norway. North East Atlantic Ocean.

Alex Mustard / A nudibranch (Flabellina lineata) feeding on a solitary hydroid (Tubularia indivisa). Gulen, Bergen, Norway. North East Atlantic Ocean.

Franco Banfi / Spirograph worm (Sabella spallanzani) Ischia Island, Italy, Tyrrhenian Sea, Mediterranean

Solvin Zankl / Oaten pipes hydroid (Tubularia indivisa), Atlantic Ocean, North West Norway

Solvin Zankl / Oaten pipes hydroid (Tubularia indivisa), Atlantic Ocean, North West Norway