Pond snails

 

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You will often see Great pond snails floating on the pond, sometimes upside down with their foot at the surface, as in the image above. They have a typical spiral shell which narrows to the tip. Spot the snorkel in the picture; they breathe oxygen.

The other large snail in the pond is the Ramshorn, easily distinguished as in this image. These snails also breathe oxygen in a single lung, regularly exposing it at the surface to take in air.

Bladder snail

Besides these two types, there are also the much smaller Bladder (or Tadpole) snails. They also take in air through a siphon and like the others can store some in their shell for buoyancy, expelling a bubble when they want to drop to the bottom of the pond.

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A ‘rout’ of Great water snails

All of our water snails offer huge benefits to the pond, feeding on algae and decaying plant detritus, so keeping the water a bit clearer and reducing deoxygenation problems somewhat.

More images and information:

Freshwater Habitats Trust: Snails