Snail updates

CC image by Africa Gomez

Of all the groups I've made pages for, the creatures I perhaps feel least able to identify are terrestrial molluscs [*in retrospect this is a lie, my experience of spiders is minimal also]. so I'm slightly worried I might have sold them short to you as a choice.

But today I offer some encouragement for those who might pick them. As I snatched some lunch in the autumn sunshine I glanced down and saw an empty shell of the snail above. I put it through the BRERC key and it rapidly and easily came out as Hygromia cinctella, the girdled snail. To be fair it has a very obvious keeled shape with a white band. But I was pleased at the painlessness of the experience.

This Mediterranean species has only been in Britain for the last 60 or so years, and was seemingly confined to the south-east until the seventies. For some reason it's spread rapidly since and has now made it as far as Scotland - apparently aided by being transported around in potplants through garden centres. It doesn't seem to be causing any problems (unlike some more nefarious introduced molluscs around the world).

Judging by the key's descriptions, it's worth noting that a lot of species are very small as adults. Some are absurdly small (there is a life-size picture of each species in the key, and some are only a millimetre high). So although you don't want to be examining a 'baby snail' thinking it's an adult, you don't want to be overlooking tiny snails just because they're small. Much careful searching is going to be necessary I think, and examination under a microscope. Do bring in your snails. I am going to keep an eye out for them too if I can.

5th October. Another snail.
I have to sort out something for my dissertation this year, so went searching for moss at the weekend. As I was clambering about, a shell caught my eye. So this is my own notebook; my own attempt to key it out:

As you can see, it was quite easy to identify. (I probably should have included some measurements of the shell). I used the BRERC snail key which is for the Bristol area, but the edge of the Salisbury Plain is not far away, and luckily this species is quite distinctive. I've run it through the FSC key and that seems to require closer attention, but it does still come out quickly.

I might also include a photo of the species and maybe an OS map clipping. Here's Pomatias elegans in an alive state:

CC image by Hectonichus

There's a distribution map for the species on the National Biodiversity Network - you can see it's certainly in the area I found it (which is encouraging). So a distribution map might be another thing for your notebook, and you can search for all sorts of things on the NBN Gateway.