Great pond snail
The shell of a great pond snail can grow up to 60mm high.
The colour of their shells varies from yellow-brown to dark brown or grey and has a pointed spire. Their skin is dark brown or grey.
Great pond snails are widespread in Britain and Europe. Also found in Asia, north Africa and North America.
Great pond snails are found in slow-moving or stagnant water, more frequent in hard water. Will tolerate slightly brackish water.
They feed on algae and rotting organic matter.
This snail deliberately ingests grains of sand which stay in its gizzard and help it break down tougher plant material that it would otherwise be unable to digest.
They can be seen floating upside-down on the surface taking in air. They can also absorb oxygen from the water through their skin. By employing these strategies the great pond snail can stay underwater for several months.
During winter these snails burrow into the soft mud and hibernate. They withdraw into their shells and secrete a thick seal over the mouth of the shell called an epiphragm. This helps to protect them from the cold until spring when they emerge again.
The eggs are laid in jelly-like capsules on aquatic plants.
They are not listed as endangered on the IUCN Red List.