Slugs, Snails & Bivalves
All images on this website have been taken in Leicestershire and Rutland by NatureSpot members. We welcome new contributions - just register and use the Submit Records form to post your photos. Click on any image below to visit the species page. The RED / AMBER / GREEN dots indicate how easy it is to identify the species - see our Identification Difficulty page for more information. A coloured rating followed by an exclamation mark denotes that different ID difficulties apply to either males and females or to the larvae - see the species page for more detail.
Slugs, Snails & Bivalves
Slugs, snails and bivalves are molluscs - a group that also includes Octopus, Squid and Cuttlefish, and one of the most successful invertebrate groups to have evolved. Most mollusc species are found in oceans but a few have adapted to live in freshwater and some can live on dry land. These terrestrial species move by secreting mucus to lubricate their path but this results in the loss of water and all are vulnerable to dessication. To avoid this they either live in damp habitats or retreat into their shells during dryer weather.
Around 100 snail and bivalve species and 25 slug species have been recorded in Leicestershire and Rutland (VC55). Others are likely to be found as some species are expanding their range and may appear in our area.
The ID resources described below are for molluscs in general. More specific help can be found in each of sections below.
Leicestershire and Rutland resources
See the section introductions below.
Keys
See the section introductions below.
If you need ID help, a great site is the Facebook - Slugs & Snails where you can submit photos and an expert will usually respond.
Other useful websites and publications
Conchological Society of Great Britain & Northern Ireland - lots of useful information including excellent photographic keys to both land and freshwater snails.
Mollusc Ireland - a quality site with excellent images and species descriptions. Covers slugs and both land and aquatic snails.
Living World of Molluscs - an interesting and detailed account of gastropod molluscs, from their biology to garden control.
Facebook - Slugs & Snails - a popular forum where you can submit photos to get ID help.
Introduction to Slugs video - excellent recorded zoom meeting by Imogen Cavadino as part of Warwickshire Wildlife Trust's outreach programme. (Fast forward to minute 14 to miss out the introductions).
Slugs and Snails, Robert Cameron (New Naturalist) - published in 2016 this is a comprehensive account of the natural history of this group.
The Land and Freshwater Molluscs of Suffolk, Ian Killeen (Suffolk Naturalist's Society)
If you know of other websites or books that you would recommend, do let us know: info@naturespot.org
Slugs
Terrestrial slugs evolved from terrestrial snails. Without a shell, slugs are are less dependent on a calcium diet and are more agile - squeezing into tight spaces. However they are more vulnerable to dessication. The slime that slugs produce helps to keep them hydrated when moving around but they need to find a moist retreat at other times.
Leicestershire and Rutland resources
Getting to Grips with Slugs & Snails - NatureSpot video guide to identifying the 10 most recorded species.
Checklist of the slugs of Leicestershire and Rutland
Keys
Identifying British Slugs - Brian Eversham
Other useful websites and publication
Slugs of Britain and Ireland (Field Studies Council - AIDGAP) - a superb up to date book, full of images and drawings, with a key, species accounts and distribution maps. Highly recommended.
Steven Falk's flickr collection - good range of slug images
Defra guide to common UK slugs
Here are a few tips of the slug features it helps to photograph. Also add a note to your record about size - this is often crucial information.
- a dorsal or oblique view of the whole animal - showing the keel if it has one and ideally with the head/tentacles extended
- a side view from the right side showing the breathing pore
- the sole (some have a central dark stripe or dark edges)
- whilst not easily photographed, the colour of the mucus can be important so stroke the slug and examine the slime on your finger!
Arionidae
Milacidae
Boettgerillidae
Limacidae
Agriolimacidae
Testacellidae
Terrestrial Snails
Leicestershire and Rutland resources
Checklist of the land snails of Leicestershire and Rutland
Guide to the Land Snails of Leicestershire and Rutland - a photographic introduction to all 50 species recorded in VC55.
Keys
Identifying British Land Snails - Brian Eversham
Other useful websites and publications
Land Snails in the British Isles - Cameron. Aidgap/FSC
Most snails can be identified from good images of their shell. Even empty shells can usually be identified and it is often easier to find these than the live animals. Try to get the angles described below and also note the size in the comments box. You can submit up to four photos with a record. You don't need to resize them, the computer will do this automatically as it uploads a copy.
- a dorsal or oblique view of the whole animal - showing the number of whorls and ideally with the head/tentacles extended
- the underside - showing the mouth opening and the umbilicus (the hole in the centre)
- a side view - the height of the shell is often a key feature
- some aquatic snails have an operculum - a shell-lid that closes over the mouth when they withdraw inside
