Wild Wonders of Europe / Smit / Great pond snail (Lymnaea stagnalis) trying to survive in ponds in broadleaf forest during dry season, Gornje Podunavlje Special Nature Reserve, Serbia, June 2009

Nick Upton / Great pond snail (Lymnaea stagnalis) grazing aquatic vegetation in a garden pond, Wiltshire, UK, February.

Nick Upton / Great pond snail (Lymnaea stagnalis) grazing aquatic vegetation in a garden pond, Wiltshire, UK, February.

Nick Upton / Great pond snail (Lymnaea stagnalis) grazing aquatic vegetation in a garden pond, Wiltshire, UK, May.

Remi Masson / Great pond snail (Lymnaea stagnalis) eating aquatic plant in a river. Alps, River Rhone, France

Laurie Campbell / Garden Snail (Helix aspersa) on rotten log in garden pond, Berwickshire, Scotland, June.

Nick Upton / Young boy looking at Pond snail he has caught in stream, held in his hand, Bristol, UK, October 2014. Model released.

Willem Kolvoort / Common water crowfoot (Ranunculus aquatilis) with Great Pond Snail (Lymnaea stagnalis) in garden pond, Holland. May.

Jan Hamrsky / Great pond snail egg mass (Lymnaea stagnalis) Europe, July, controlled conditions

Jan Hamrsky / Great pond snail (Lymnaea stagnalis) Europe, July, controlled conditions

Jan Hamrsky / Great pond snail (Lymnaea stagnalis) Europe, July, controlled conditions

Wild Wonders of Europe / Lundgren / Great pond snail (Lymnaea stagnalis) Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Water boatman (Corixidae) on a Great pond snail (Lymnaea stagnalis), Danube Delta, Romania, June.

Wild Wonders of Europe / Lundgren / Great pond snail (Lymnaea stagnalis) Danube Delta, Romania, June.

Simon Colmer / Great Pond Snail (Lymnaea stagnalis) on white background, UK

Simon Colmer / Close-up of eggs in egg case of Great Pond Snail (Lymnaea stagnalis), captive UK

Simon Colmer / Great Pond Snail (Lymnaea stagnalis) egg case, captive UK

Simon Colmer / Great Pond Snail (Lymnaea stagnalis) on pond plant, captive UK

Willem Kolvoort / Great pond snail (Lymnaea stagnalis) at water surface to breathe, garden pond, Holland

Willem Kolvoort / Great pond snail (Lymnaea stagnalis) and two Great ramshorn snails (Planorbis corneus) under leaf of White water lily (Nymphaea alba) garden pond, Holland

Willem Kolvoort / Great ramshorn snail (Planorbis corneus) sand winning pit, Holland

Willem Kolvoort / Great pond snail (Lymnaea stagnalis) at surface to breathe, sand winning pit, Holland.

Willem Kolvoort / Stone loach (Nemacheiulus barbatula) and Great pond snail (Lymnaea stagnalis) in brook in Holland

Willem Kolvoort / Great pond snails (Lymnaea stagnalis) with European edible frog spawn (Rana esculenta) Holland

Willem Kolvoort / Great ramshorn snail (Planorbis corneus) sand winning pit, Holland. This snail does not have enough pigment in its skin, the red colour is caused by haemaglobin.

Willem Kolvoort / Great Pond Snail (Lymnaea stagnalis) underwater, scraping the algae off stem of White Water Lily (Nymphaea alba} peatbog lake, Holland

Willem Kolvoort / Great ramshorn snail (Planorbis corneus) feeding on alage on growing leaf of Yellow water lily, Lake Naarden, Holland

Willem Kolvoort / Great ramshorn snail (Planorbis corneus) feeding on alage on leaf, Lake Naarden, Holland

Willem Kolvoort / Great ramshorn snail (Planorbius corneus) feeding on algae on growing water lily leaf, Holland

Willem Kolvoort / Great Pond Snail (Lymnaea stagnalis) Holland

Willem Kolvoort / Great Pond Snail (Lymnaea stagnalis) on Water lily leaf in garden pond, Holland

Willem Kolvoort / Great Pond Snail (Lymnaea stagnalis) and Caddis fly larva on stems of Bulrush, peat bog, Holland

Willem Kolvoort / Reflection of Great Pond Snail (Lymnaea stagnalis) floating on water surface, Holland. Pond Snails have lungs and from time to time they float on the surface to breath. After this they can stay for qu...

Willem Kolvoort / Great ramshorn snail (Planorbius corneus) feeding on algae on plant, Holland

Willem Kolvoort / Great Pond Snail (Lymnaea stagnalis) shell covered in algae, Holland

Willem Kolvoort / Great ramshorn snail (Planorbius corneus) feeding on algae on plant, Holland

Simon Colmer / Great Pond Snail (Lymnaea stagnalis) UK

Kim Taylor / Great pond snail at water surface showing spiracle {Lymnaea stagnalis} UK.

Kim Taylor / Great pond snail underwater {Lymnaea stagnalis} UK.

Jane Burton / Two Great pond snails {Lymnaea stagnalis}. UK.

Adrian Davies / Great pond snail {Lymnaea stagnalis} England, UK

Adrian Davies / Great pond snail (Lymnaea stagnalis). England, UK, Europe

Konrad Wothe / Great Pond Snail (Lymnaea stagnalis) at surface, Upper Bavaria, Germany

Julian Hume / Illustration of view of Makauwahi Sinkhole from the southwest side as it might have appeared 3000 years ago,prior to human arrival. On left side,a flock of turtle-jawed moa-nalo (Chelychelynechen quas...

Henley Spiers / Ear pond snail (Lymnaea auricularia) balancing on the tip of a stem underwater, River Otter, Devon, England, UK.

Will Watson / New Zealand mud snail / Jenkin's spire snail (Potamopyrgus antipodarum), Malvern pond, Worcestershire, England, UK. March. Controlled conditions.

Georgette Douwma / Common frog (Rana temporaria) tadpoles feeding on Common garden snail (Helix aspersa) which has fallen in the water; small pond snails on its shell, London, England, UK. May.

Nick Upton / Two Great pond snails (Lymnaea stagnalis) grazing algae from submerged rocks in a garden pond, Wiltshire, UK, July.

Nick Upton / Great pond snail (Lymnaea stagnalis) grazing algae from a rock in a garden pond, Wiltshire, UK, July.

Andy Sands / Snail Killing Fly (Sciomyzidae sp.) perched on reed stem above pond, Hertfordshire, England, UK, August

Andy Sands / Snail killing fly (Sciomyzidae sp.) perched on reed stem above pond, East Sussex, England, UK, July. Focus Stacked