Olga Kamenskaya / Stalked Jellyfish (Lucernaria quadricornis) Svalbard, Norway, September.

Nick Upton / Stalked jellyfish (Lucernariopsis campanulata), a BAP protected species, clinging to seaweed in a rockpool, near Falmouth, Cornwall, UK, September.

Alex Mustard / Dense growth of Bootlace seaweed (Chorda filum) in shallow water, with a Stalked jellyfish (Calvadosia sp). clinging on between strands, Kimmeridge, Dorset, England, UK, English Channel. July.

Alex Mustard / Small Stalked jellyfish (Calvadosia sp.) attached to Bootlace weed / Mermaid's hair (Chorda filum), Pendennis Head, Cornwall, UK. English Channel.

Alex Mustard / Detail of a St John's stalked jellyfish (Calvadosia cruxmelitensis) growing on seaweed, Chesil Beach, Dorset, UK, English Channel.

Alex Mustard / Stalked jellyfish (Calvadosia campanulata) growing on seaweed, Porthkerris, Cornwall, UK, English Channel.

Pascal Kobeh / Horned stalked jellyfish (Lucernia quadricornis) on the bottom. It is small funnel-shaped jellyfish that is attached on the bottom by sucker, Russia. White Sea.

Pascal Kobeh / Horned stalked jellyfish (Lucernia quadricornis) on kelp. It is small funnel-shaped jellyfish that is attached on the bottom by sucker, Russia. White Sea.

Pascal Kobeh / Horned stalked jellyfish (Lucernia quadricornis) on kelp. It is small funnel-shaped jellyfish that is attached on the bottom by sucker, Russia. White Sea.

Pascal Kobeh / Horned stalked jellyfish (Lucernia quadricornis) on kelp. It is small funnel-shaped jellyfish that is attached on the bottom by sucker, Russia. White Sea.