Saving England's most threatened species from extinction

Little Whirlpool Ramshorn Snail

Anisus vorticulus

Less than
mm in diameter
Found in
ditches at the RSPB's Pulborough Brooks Reserve in 2013/14
Now in only
main populations in the UK

What is a Little Whirlpool Ramshorn Snail?

Its name is surely bigger than the animal itself! This aquatic snail is rarely more than 5mm in diameter, but it’s one of the rarest, most restricted and most vulnerable freshwater molluscs in Britain.

It has very particular requirements; it needs unpolluted, chalky waters such as marshland ditches, with just the right vegetation. Once found in about 15 sites in south-east England, it’s now largely restricted to just three.

Why are they in trouble?

Loss of suitable wetlands is part of the problem, but also inappropriate management of remaining wetlands and poor water quality. They don’t like cloudy or polluted water. It’s possible that the presence of carp at some sites is a problem, as these fish tend to stir up the sediment.

How we will help the Little Whirlpool Ramshorn Snail?

This Back from the Brink project is led by the RSPB. The Arun Valley in West Sussex is one of the few strongholds for this snail. We are managing ditches to provide good habitat, and we’ll be creating more. We’ll test factors that may affect whether or not a ditch will be suitable for the species, so that we understand better how to help it. And we’ll investigate how cloudy the water is and whether carp are causing the problem.
We’ll monitor how this little snail is getting on wherever it is living, and we may also try reintroducing some into parts of its former range at RSPB Pulborough Brooks nature reserve.

What we’re aiming for

By the end of the Project, we want to understand more about the habitat requirements of the Little Whirlpool Ramshorn Snail, and how to provide them. We aim to keep all of the current populations healthy, and encourage the snail to spread into new areas.

How to get involved

Can you help us monitor the state of our ditches and tell people about the need for clean water?

You can get the latest news, and find out about upcoming events, by following the links below.

Project timeline

Summer 2020

Monitoring water quality

Autumn 2020

Monitoring for snails

Spring 2021

End of project review and sharing of results

Project contact

Jane Sears

Project Officer

Latest news

Get Involved

Little Whirlpool Ramshorn Snail (Anisus vorticulus)

The Last Ditch

Pulborough Brooks Reserve
Read More

Bringing them Back From The Brink

We are working with some of the most endangered species in England. With your help we can do even more to save them.

Project lead

Delivery partners