Philippe Clement / Lined top shells (Phorcus lineatus) in a rock pool, Normandy, France, June

Philippe Clement / Lined top shells (Phorcus lineatus) and Common european limpets (Patella vulgata) in a rock pool, Normandy, France, June.

Theo Bosboom / Sea snail (Trochidae family) scraping the rocks for algae, in a small tidal pool, near Aljezur, Portugal. May 2017

Nick Upton / Thick / Toothed top shell (Phorcus lineatus), five exposed on rock at low tide. Cornwall, England, UK. September.

Paul Bertner / Slug, Montagne D'Ambre National Park, Madagascar

Robert Thompson / Painted top shell (Calliostoma zizyphinum) and Common barnacle (Semibalanus balanoides) on rock at edge of Strangford Lough. Mill Quarter Bay, Killard Point National Nature Reserve, Strangford, County...

Richard Herrmann / Bat Star (Asterina miniata) group and sea snails feeding on Ocean Sunfish (Mola mola) that was killed by California Sea Lion (Zalophus californianus), Monterey Bay, California

Sue Daly / Painted top shell (Calliostoma zizyphinum) Trondheimsfjord, Norway, July.

Paul Bertner / Leatherleaf Slug (Veronicellidae), new species, Ranomafana National Park, Madagascar

Paul Bertner / Leatherleaf Slug (Veronicellidae), new species, Ranomafana National Park, Madagascar

Paul Bertner / Army Ant (Leptogenys sp) group attacking snail, Angkor Wat, Cambodia

Nick Upton / Common prawns (Palaemon serratus) scavenging on a damaged Flat top shell (Gibbula umbilicalis) in a rockpool, Cornwall, England, UK, September.

Nick Upton / Cushion star (Asterina gibbosa) moving in a rockpool near a Flat top shell (Gibbula umbilicalis) and a Common prawn (Palaemon serratus), Cornwall, England, UK, September.

Nick Upton / Cushion star (Asterina gibbosa) moving in a rockpool near some Flat top shells (Gibbula umbilicalis), Cornwall, England, UK, September.

Franco Banfi / Blue top snail (Calliostoma ligatum), Alaska, United States, North Pacific Ocean.

Sandra Bartocha / Pyramidal Orchid (Anacamptis pyramidalis) with snail (Discidae) in Pollino National Park, Italy. May.

Ingo Arndt / Land Snail (Polymita picta) group for sale, Cuba

Ingo Arndt / White Gardensnail (Theba pisana) mass clustered on vegetation during dry season to avoid warm temperatures at ground level, Camargue, France

Ingo Arndt / Land Snail (Caracolus sagemon), Cuba

Pete Oxford / Nudibranch (Phyllidia coelestis), Cenderawasih Bay, West Papua, Indonesia

Ingo Arndt / White Gardensnail (Theba pisana) mass clustered on vegetation during dry season to avoid warm temperatures at ground level, Camargue, France

James Christensen / Triclad (Obama sp) feeding on land snail, Septimo Paraiso Cloud Forest Reserve, Mindo, Ecuador

James Christensen / Triclad (Obama sp) feeding on land snail, Septimo Paraiso Cloud Forest Reserve, Mindo, Ecuador

Alex Hyde / Detail of Purple Topshell (Gibbula umbilicus) found washed up on a beach. Claigan, Isle of Skye, Inner Hebrides, Scotland, UK. April.

Hiroya Minakuchi / Snail (Euhadra peliomphala) on Hydrangea (Hydrangea sp) flower, Japan

Pete Oxford / Whelk (Buccinidae) egg casings, Little Saint Simon's Island, Georgia

Sue Daly / Pennant's Topshell (Gibbula pennanti) and Purple Topshell (Gibbula umbilicalis) sea shells on beach, showing difference between species, sea shells on beach, Sark, British Channel Islands.

Sue Daly / Purple Topshell (Gibbula umbilicalis) sea shells on beach, Sark, British Channel Islands.

Sue Daly / Purple Topshell (Gibbula umbilicalis) sea shells on beach, Sark, British Channel Islands.

Sue Daly / Pennant's Topshell (Gibbula pennanti) sea shells on beach, Sark, British Channel Islands.

Sue Daly / Painted top shell (Calliostoma zizyphinum) on seashore, Sark, British Channel Islands.

Sue Daly / Thick top shells (Osilinus lineatus) on sea shore, Sark, British Channel Islands.

Sue Daly / Thick top shell (Osilinus lineatus) on rocks on sea shore, Sark, British Channel Islands.

Sue Daly / Grey Topshell (Gibbula cineraria) on sea shore, Sark, British Channel Islands.

Piotr Naskrecki / Weaver Ant (Oecophylla sp) group carrying snail to their nest, Gorongosa National Park, Mozambique

Piotr Naskrecki / Lantern Bug (Druentia variegata) trio camouflaged on bark with snails, Gorongosa National Park, Mozambique

Mark Moffett / Land Snail (Enidae) group gathered on tree to escape heat and carnivorous beetles, Zahr Plain, Socotra, Yemen

Ingo Arndt / Cone Top Shell (Tectus conus) from Indo-Pacific, Meeresmuseum Ozeania, Riedenburg, Germany

Duncan Usher / Turbinate Monodont (Monodonta turbinata) shells collected from North Sea seen in ultraviolet light, Spain. Sequence 2 of 2

Duncan Usher / Turbinate Monodont (Monodonta turbinata) shells collected from North Sea, Spain. Sequence 1 of 2

Solvin Zankl / The shells of the minute sea snail (Schwartziella ephamilla, top) and the wentletraps (Cycloscala hyalina, below) from sand sample from Raja Ampat, Indonesien. Diagonal of frame approx. 2 mm Digital f...

Chris Newbert / Nudibranch (Halgerda malesso) skin, Indonesia

Norbert Wu / Sea Snail (Nacella concinna) on Brown Algae (Cystosphaera jacquinotii) blade, Palmer Station, Antarctic Peninsula, Antarctica

Konrad Wothe / Snail (Zonitidae) on dew covered grass, Bavaria, Germany

Steve Gettle / Land Snail (Drymaeus sp), Ecuador

Norbert Wu / Cockscomb Nudibranch (Janolus barbarensis), Vancouver Island, British Columbia, Canada

Alex Mustard / 2020VISION / Grey topshell (Gibbula cineraria) snail on a kelp frond with small periwinkle in foresgroung, on the wreck of the MV Lunokhods, Shetland Islands, Scotland, UK, June.

Pete Oxford / Lettuce Sea Slug (Elysia crispata), Bonaire, Netherlands Antilles, Caribbean

Kevin Schafer / Banana Slug (Ariolimax columbianus) on trunk of Island Oak (Quercus tomentella), Channel Islands National Park, California

Birgitte Wilms / Cowry (Aclyvolva sp) camouflaged on Soft Coral (Ctenocella sp), Papua New Guinea

Birgitte Wilms / Nudibranch on coral, Solomon Islands

Pete Oxford / Flamingo Tongue Snail (Cyphoma gibbosum), Quintana Roo, Mexico

Chien Lee / Land Snail (Amphidromus sp), endemic to limestone karst formations, Bukit Sarang Conservation Area, Bintulu, Borneo, Malaysia

Mark Moffett / Marauder Ant (Pheidologeton diversus) minor workers carrying snail, Singapore

Albert Lleal / Cuba Garden Zachrysia (Zachrysia provisoria) snail, native to Cuba

Ingo Arndt / Grey Garden Slug (Derocerasáreticulatum) eggs with hatchlings, Germany

Mark Moffett / Ant (Formicidae) predating on snail, Ecuador

Sebastian Kennerknecht / California Mussel (Mytilus californianus) clusters, Barnacles (Balanus sp), Black Turban Snails (Tegula funebralis), Rockweed (Fucus sp), and Sea Lettuce (Ulva sp) in high tide zone, Santa Cruz, Monte...

Hiroya Minakuchi / Magnificent Chromodorid Nudibranch (Chromodoris magnifica), Celebes Sea

Fred Bavendam / Black Velutinid (Coriocella nigra) nudibranch, Manado, Sulawesi, Indonesia

Fred Bavendam / Spanish Dancer (Hexabranchus sanguineus) nudibranch pair mating, Hawaii

Fred Bavendam / Allied Cowry (Phenacovolva recurva) camouflaged on coral, Bali, Indonesia

Norbert Wu / Purple-ring Top Snail (Calliostoma annulatum) attacking Strawberry Anemone (Corynactis californica), Monterey, California

Norbert Wu / California Aglaja (Navanax inermis) sea slugs mating, southern California

Norbert Wu / Purple-ring Top Snail (Calliostoma annulatum) attacking Strawberry Anemone (Corynactis californica), California

Norbert Wu / White-and-orange-tipped Nudibranch (Janolus fuscus), Alaska

Norbert Wu / Multicolor Frond-aeolis (Dendronotus diversicolor) nudibranch, foraging on hydroids, Alaska

Lynda Harper / Rainbow Abalone (Haliotis iris), inside shell, New Zealand

Albert Lleal / Strawberry Top Shell (Clanculus pharaonius), native to the Red Sea

Albert Lleal / Strawberry Top Shell (Clanculus pharaonius) photographed under ultraviolet light showing fluoresence, native to the Red Sea

Thomas Marent / Land Snail (Helicella sp) group on Milk Thistle (Silybum marianum), Camargue, France

Duncan Usher / Edible Snail (Helix pomatia) is source of escargot, Europe

Hiroya Minakuchi / Cowry (Pseudosimnia punctata) living on soft coral, Sulu Sea, Borneo, Malaysia

Norbert Wu / Purple-ring Top Snail (Calliostoma annulatum) pair on kelp bulb, these snails mate at the top of the kelp canopy, California

Fred Bavendam / Top Shell (Trochus sp) snail standing up while spawning on the reef at night, Bali, Indonesia

Piotr Naskrecki / Edible Snail (Helix pomatia), Poland

Piotr Naskrecki / Fig (Ficus sp) fruit cross-section with Fig Wasp (Ceratosolen capensis) males that have developed inside fruit, Blyde River Canyon, South Africa

Piotr Naskrecki / Fig (Ficus sp) fruit with parasitic wasp, Blyde River Canyon, South Africa

Piotr Naskrecki / Clouded Snake (Sibon nebulatus) feeding on snail prey, Costa Rica

Richard Herrmann / Bat Star (Asterina miniata) group and sea snails feeding on Ocean Sunfish (Mola mola) that was killed by California Sea Lion (Zalophus californianus), Monterey Bay, California

Heidi & Hans-Juergen Koch / Chocolate Arion (Arion rufus) group collected by Sabine Mlynek, who uses them in traditional bronchitis medicine for Domestic Horses (Equus caballus), Germany

Pete Oxford / Nudibranch eggs, Raja Ampat Islands, Indonesia

Pete Oxford / Nudibranch (Tambja sp), new species, Raja Ampat Islands, Indonesia

Pete Oxford / Nudibranch (Glossodoris atromarginata), Raja Ampat Islands, Indonesia

Pete Oxford / Nudibranch (Aegires gardineri) pair laying eggs, Raja Ampat Islands, Indonesia

Piotr Naskrecki / Weaver Ant (Oecophylla sp) group carrying snail to their nest, Gorongosa National Park, Mozambique

Mark Moffett / Snail, Kilisan Wadi, Momi, Socotra, Yemen

Birgitte Wilms / Nudibranch (Phyllodesmium longicirrum), Papua New Guinea

James Christensen / Snail, Andes, Ecuador

Fred Bavendam / Opalescent Nudibranch (Hermissenda crassicornis) on Taylor's Colonial Tunicates (Metandrocarpa taylori), British Columbia, Canada

Duncan Usher / Flat Topshells (Gibbula umbilicalis), Common Northern Whelk (Buccinum undatum), and Common Periwinkle (Littorina littorea) shells

Tony Wu / Female Pfeiffer's top shell (Tegula pfeifferi) broadcast spawning, from elevated spot in raised vertical position, by ejecting clusters of green eggs. East China Sea, Kagoshima Prefecture, Japan...

Tony Wu / Male Pfeiffer's top shell (Tegula pfeifferi) broadcast spawning by dribbling sperm into water little by little. East China Sea, Kagoshima Prefecture, Japan.

Joel Sartore / Photo Ark / Jujube top snail (Calliostoma jujubinum) portrait, Gulf Specimen Marine Lab and Aquarium.

Joel Sartore / Photo Ark / Jujube top snail (Calliostoma jujubinum), ventral view, Gulf Specimen Marine Lab and Aquarium.

Shane Gross / Blue topsnail (Calliostoma ligatum) and other snails feeding on the eggs of the Leafy hornmouth (Ceratostoma foliatum), Vancouver Island, British Columbia, Canada, Pacific Ocean.