Pascal Kobeh / Pleurobranch nudibranch (Pleurobranchus forskali) Sulu Sea, Philippines

Linda Pitkin / Side-gilled slug, Pleurobranch (Pleurobranchus grandis), at night Gordon Reef, Straits of Tiran, Egypt, Red Sea

Constantinos Petrinos / Side-gilled slug (Pleurobranchus mammalatus) Lembeh Strait, North Sulawesi, Indonesia.

Sue Daly / Yellow-plumed sea slug (Berthella plumula) Sark, British Channel Islands.

Tim Laman / Side gilled slug (Berthella martensi) on coral reef, Malapascua Island, Visayan Sea, Philippines

Fred Bavendam / Pleurobranch (Pleurobranchus sp) sea slug, Manado, Sulawesi, Indonesia

Constantinos Petrinos / Side-gilled slug / Seaslug {Euselenops luniceps} from above, Sulawesi, Indonesia

Juergen Freund / Sea slug (Pleurobranchus grandis) Indo Pacific

Juergen Freund / Fast swimming ophistibranch sea slug{Euselenops luniceps} Indo-Pacific

Juergen Freund / Side gilled slug {Berthella martensi} Indo-Pacific

Constantinos Petrinos / Seaslug on seabed {Euselenops luniceps} Sulawesi Indonesia. Indo Pacific

Alex Mustard / Two Moon-faced seaslugs (Euselenops luniceps) emerging from the sandy seabed at night, Bitung, North Sulawesi, Indonesia, Molucca Sea.

Francisco Marquez / Nudibranch(Berthellina ilisima) on white background, Islas Marias Archipelago, Marias Biosphere Reserve, Mexico.