Our projects


Pond mud snail conservation breeding programme

Pond mud snail conservation breeding programme

The pond mud snail (Omphiscola glabra) is a very small species of freshwater aquatic snail, about the size of a fingernail, that typically lives in temporary habitats like ponds, marshes, and small ditches. 

Once widespread across acidic lowlands in England and Wales and recorded as far north as Perthshire in Scotland, pond mud snails are very rare and distribution is currently limited to a handful of few thinly spread sites in Scotland, England, and Wales. As a result of this decline, pond mud snails are listed as a Vulnerable species in the UK Red Data Book.

One of the sites where these little snails persist is the Pentland Hills, right across from Edinburgh Zoo - in fact, you can see it from the viewpoint on top of the hill during your next visit!

The main reasons for the pond mud snail’s decline are habitat loss and pollution.

Pond mud snails form a crucial part of the complex network of living organisms inhabiting temporary freshwater ecosystems in Scotland and contribute to their healthy functioning. These habitats support other species that, like the pond mud snail, are adapted to survive periods of drought by burying into the mud and becoming inactive until the pond becomes wet again. Pond mud snails are good waste recyclers, eating a lot of algae and decaying matter. Typically found in very clean water, they are also an important indicator species for ephemeral, temporary freshwater habitats.

How RZSS is helping

Edinburgh Zoo is home to a growing population of pond mud snails that are part of our conservation breeding programme. We have been successfully breeding pond mud snails in our dedicated facility since 2017.

During that time, we have greatly enhanced existing knowledge of how to care for this species so that it thrives and breeds.

In 2018, RZSS conducted a release of pond mud snails into Edinburgh's Pentland hills, and are now hoping to run a bigger, more long-term release program to this site.

As part of that program, we carry out monthly monitoring of the Pentlands site to gain a better understanding of the conditions the pond mud snails encounter in their natural habitat, and gather knowledge to inform our decisions on further releases.

Over the next few years, we plan to expand our work on the species and conduct annual releases into the Pentlands. This would give a much-needed boost to the population of snails that call this site home. Our long-term goal is to improve the overall conservation status of the species in Scotland.

Invertebrates are in decline globally, which has profound consequences for the healthy functioning of ecosystems. RZSS is determined to stand up for the little guys when it comes to species conservation and to run programmes that help reverse this decline.

Find out more