Sue Daly / Candy striped flatworm (Prostheceraeus vittatus) laying eggs, Isle of Man, July.

Alex Mustard / Undescribed species of flatworm (Cycloporus sp.) crawls over a sea squirt. Mioskon Island, Raja Ampat, West Papua, Indonesia. Dampier Strait. Tropical West Pacific Ocean

Sue Daly / Candy striped flatworm (Prostheceraeus vittatus) Guillaumesse, Sark, British Channel Islands.

Georgette Douwma / Marine flatworms (Cycloporus venetus) on Blue stalked sea squirt / tunicate, Rinca, Komodo National Park, Indonesia, October

Georgette Douwma / Marine flatworm (Cycloporus venetus) on Blue stalked sea squirt / tunicate with egg mass. Rinca, Komodo National Park, Indonesia, October

Alex Mustard / Flatworm (Cycloporus sp.) resting inside a Sea squirt (Didemnum molle) on a coral reef, Raja Ampat, West Papua, Pacific Ocean.

Franco Banfi / Flat worm (Prostheceraeus sp.) on coral, rare albino species which inhabits poorly lit environments, Vis Island, Croatia, Adriatic Sea, Mediterranean.