Clausilia dubia - ID confirmation please

[Nettle Runner]

17 April 2010 Hawks Wood, Thorpe Salvin

Can anyone confirm my tentitive ID of this snail?
The area in which it was found is on limestone, bl woodland with a stream closeby.



Les

[Fauna]

Not quite sure on this one as one of its key id features is obscured in its mouth.

Any idea on its size?

Adult C.dubia will be larger than C.bidentata

[Nettle Runner]

Hi Fauna and thanks for taking the time to comment on my image.

I estimate the length to be about 12-15mm.
Here is another view if that will help.



What is the key ID feature you are refering to, just so that I can include same in any future shots of snails.

Again, thanks for your assistance.
Les

[Fauna]

The size could be right, anything over 14mm then you will have C.dubia.

But i'm still unsure on your specimen. The key feature which i was looking for is obscured by some soil particles...they are hiding the Columellar lamella, this will be more conspicuous in C. dubia to that of C. bidentata, it will also contain a notch that C.bidentata will lack.

C.dubia will also have spiral striations, i'm not sure if your specimen has these?


In general if you looking to id long spire type snails it is best to get good views inside their mouth, they may contain teeth and other features key to their id. While other snails it is best to take a look at thier umbilicus.

[Nettle Runner]

Many thanks Fauna for taking the time to point out the essential features to include in photos for ID purposes. I will certainly watch out for these in my next attempt.
Les

[bigdave60dog]

Clausilia often present ID problems. There is nice web page that will often help with shell features. If you Google in Clausilia UK, then onto "Shell Catalogue"
You will get a comprehensive series of ?definitive photos.
When all else fails, if it is the right size and shape call it "Bidentata". 90% of the time you will be right.
Without holding the thing I can`t be sure but yours don`t have the jizz of a Bidentata though. You could be right.
Dave

[Leeeds lad]

Sorry but this is Clausilia bidentata although a largish example. Clausilia dubia cravenensis is only found in the limestone dales of Yorkshire Cumbria and in some parts of Durham; well apart from a colony at Dover castle that is.
Leeds lad