Pond mud snail

When: All year round

Scientific name: Omphiscola glabra

Size: Adult shells can be between 12 and 20mm in length

Where: Freshwater ponds and pools - often in nutrient poor environments.

We are lucky in the Inner Forth to be home to one of Scotland's most scarce invertebrate species - the Pond mud snail! This snail is only known to seven sites in Scotland, although it was once widespread. Modern farming practises and land development have led to a loss of habitat for this little invertebrate, however action is being taken to help the species thrive in the Inner Forth, and hopefully lead to an increase in numbers further afield. 

Although perhaps not the most awe inspiring upon first sight, the pond mud snail has many incredible characteristics and behaviours that make it an essential part of any freshwater ecosystem. Small, brown, with a beautiful elongated conical shell, these snails favour pools and ponds that are typically low in nutrients, and even prone to drying out in the hotter summer months. The snails are able to survive in these conditions by burying themselves in the mud, storing a little water in a cavity in their shell, from which they can get oxygen until water returns to the pool.

The pond mud snail is also a hermaphrodite, meaning that it is able to lay and fertilise its own eggs; essentially reproducing by itself! This makes the species a prolific breeder, with an individual laying between 10 - 30 eggs in February, taking around 25 days to hatch. This frequency of breeding has typically made them an enemy of many garden pond owners, fearing that the snails may wreak havoc amongst their prized freshwater plants. Although pond mud snails aid the decomposition of dead leaves and other material that can build up at the bottom of pools and ponds, they are able to survive in very low nutrient waters, and will also feed off some algae, making them more favourable in the eyes of pond perfectionists.

Despite their amazing adaptations to surviving in such variable and often harsh conditions, pond mud snails are in decline. A combination of factors including loss of habitat and pollution from chemicals used in modern farming practises has led to a vast and rapid decrease in the snail's presence in Scotland. Historically widespread throughout the south, it is now only known to seven areas in Scotland, two of which border the upper Firth of Forth. Thankfully, Buglife Scotland are leading the way to conserving this sought after species by running a number of activities through their Marvellous Mud Snails project. Visit their website to learn more and find out how you can be involved! https://www.buglife.org.uk/local/marvellous-mud-snails

Image: Paul Baker, Buglife