Slug or snail of the day

[Yashca]

The snail was found near the base of a trunk of a tree, in an area of woodland known as Peggy Farrow, East Yorkshire, quite near the Humber. Unfortunately when I noted down the size I wrote '12/13mm'.

[Andestine]

Hi Yashca,

So glad you posted, as following the responses your received I now have both books winging their way to me

Love your snail. I've never seen one like that around here. Will raise you another kind of snail tomorrow

Cheers,

Andestine

[theresa dockery]

Originally Posted by Andestine

Does anyone know what kind of pigment that is, and (because of the mollusc connection) whether they’re like shellfish and get their colours from the food they eat? Could this bright orange be a carotenoid or something similar? And where does the Glossy Glass Snail get the blue colour from, or is it born with it?

A very interesting question - try these links:

This paper investigates the effects of diet on the yellow/orange pigmentation of Carinarion slugs (previously part of the genus Arion).
FOOD-INDUCED BODY PIGMENTATION QUESTIONS THE TAXONOMIC VALUE OF COLOUR IN THE SELF-FERTILIZING SLUG CARINARION SPP ? J MOLLUS STUD

The skin pigment in Arion ater is thought to be uroporphyrin 1.
Cambridge Journals Online - Abstract

An interesting article on the diverse range of pigments found in molluscan shells:
THE PIGMENTATION OF MOLLUSCAN SHELLS - COMFORT - 2008 - Biological Reviews - Wiley Online Library

[Andestine]

Originally Posted by theresa dockery

A very interesting question - try these links:

This paper investigates the effects of diet on the yellow/orange pigmentation of Carinarion slugs (previously part of the genus Arion).
FOOD-INDUCED BODY PIGMENTATION QUESTIONS THE TAXONOMIC VALUE OF COLOUR IN THE SELF-FERTILIZING SLUG CARINARION SPP ? J MOLLUS STUD

The skin pigment in Arion ater is thought to be uroporphyrin 1.
Cambridge Journals Online - Abstract

An interesting article on the diverse range of pigments found in molluscan shells:
THE PIGMENTATION OF MOLLUSCAN SHELLS - COMFORT - 2008 - Biological Reviews - Wiley Online Library

Theresa, you're a saint! (no pun intended )
I'm so glad that you find it an interesting question too. The whole subject of pigment chemistry is fascinating and even has a very basic practical application for me as I want to learn how to preserve the colours of things like seashells and crab shells from fading, if possible.

The first article was very interesting with its talk of pigment variation due to age, food or climate apart from genetics. I would love to know how climate changest things. And the experiment had rather unexpected results, though it did suggest that using colour traits to distinguish between different species of slugs may not be a very reliable method due to the effects of different diets on pigmentation.

The second article is above my current level of knowledge about pigments, but the fact that porphyrins are shared by some land and marine invertebrates is well worth knowing.

I would love to have the full article of the third one, but, unfortunately it requires Athens again and my last sub ran out in 2000 But noting the author made me smile as I had another one of his books for many years, and never really thought about him writing on any other topics at the time

Thanks again, Theresa, and I'm just off to hunt for some more snail images, as promised earlier...

Cheers,

Andestine

[Andestine]

Originally Posted by The Woodman

Hardly snail of the day but the word aestivation cropped up recently and I thought I'd dig out a holiday snap from a couple of years ago. Whilst grubbing about the perimeter garden wall of the Mull of Galloway lighthouse I noticed thousands of aestivating garden snails. No other specie was present and there were groups centered on every depression in the wall surface. I'm going back there at New Year and will try to find out where they go in the winter. It's a harsh environment on the end of the peninsula.




There was an interesting thread a while ago about aestivating snails on a tree trunk.

I was very glad to see you posting that as I’d been meaning to learn more about aestivation ever since Harry introduced me to the word So I found some more interesting photos of snails aestivating, but all in hot countries, so I’m very curious to know why yours were aestivating close to the Mull of Galloway lighthouse, for goodness’ sakes!

I’ll also be very interested to hear what you discover about their choice of winter shelter. As you say, a harsh environment indeed.

I’m posting these snails at the tail end of this post as I know you have a fondness for the little banded ones. I have no idea what the last one is though, but I love the patterns on its shell. I always find them on sandy dunes near the sea.

Cheers,

Andestine

P.S. Apologies once again for the poor photos. Will do better over time









(Snailus semaphorus )

[The Woodman]

The signalling snail is probably a little disgruntled by your attentions and is politely telling you to go away by semaphoring a "V". It's a clever snail because it knows that if it were to show a "V" you would interpret that as a semaphored "U" and not be any the wiser.

I trust you can follow that!

The Chinese call it 蜗牛交谈 and take it very seriously.

[Andestine]

Originally Posted by The Woodman

The signalling snail is probably a little disgruntled by your attentions and is politely telling you to go away by semaphoring a "V". It's a clever snail because it knows that if it were to show a "V" you would interpret that as a semaphored "U" and not be any the wiser.

I trust you can follow that!

The Chinese call it 蜗牛交谈 and take it very seriously.

Noble Woodman,

You will not lead me astray, and as my response is definitely not fit for the tender ears of any little ones with their curiosity about molluscs, I shall send you a PM later so that you can judge how well I followed your translation of the mollusc's attempts at communicating its displeasure at your leisure

But in the meantime, I am still intrigued as to why your snails were aestivating so far north of the equator?

Couched in language I can follow, of course

Oh, and what exactly is the mystery about Chinese Mystery Snails?

Cheers,

Andestine

[The Woodman]

M'lady

I'm intrigued too. To aestivate in such exposed conditions in the face of the prevailing weather and potential salt laden washings which as we all know is usually anathemic to the curly coated critters, I cannot imagine why. In the garden summer aestivation is usually noted in the security of the underside of pots and the like, well away from the glare of direct sunlight.

I have seen this behaviour in European climes in the heat of summer, snails clinging to the very tops of plants where one would think that due to the enterprise of solar radiation, body fluids would evaporate through thin shells and the hapless occupant perish. An example of Spanish snails here....



I'm prompted to do some digging with this one.

As for the ability to prophesying predilictions of our far eastern sino-kin using the movements of helical housed crawlers, you wouldn't be suprised to hear me link that activity with the rest of the mystery and magic brigade.

p.s. Note how the occupants of the Agave have arranged themselves according to size. How do they do it?

[Andestine]

Originally Posted by The Woodman

M'lady

I'm intrigued too. To aestivate in such exposed conditions in the face of the prevailing weather and potential salt laden washings which as we all know is usually anathemic to the curly coated critters, I cannot imagine why. In the garden summer aestivation is usually noted in the security of the underside of pots and the like, well away from the glare of direct sunlight.

M'Lord,

Apologies for the delay in replying, but I have been spending some time out in the snow with sugar spray and camera, and keeping company with other invertebrates...

As for salt lashings and snails, I'd never thought of that before. My by-the-sea snail (which I mistakenly placed as no.4 instead of no.2 in my last post) loves to feed on sea radish and regularly gets covered in salt spray as our islands are often stormy. So how do they resist being pickled?

The snow has held up delivery of the two books recommended here of late, but when they arrive I hope to be able to ID the salt-resisting one.

But can you call the daily retreat of garden snails under pots aestivation? I thought it would only apply to summer-long dormancy? But I'm happy to be corrected...I have always assumed that they spring back to life every night, or when it's wet. But although that's probably exposing my complete ignorance about snail behaviour, I dont mind as it's the only way to learn

I have seen this behaviour in European climes in the heat of summer, snails clinging to the very tops of plants where one would think that due to the enterprise of solar radiation, body fluids would evaporate through thin shells and the hapless occupant perish. An example of Spanish snails here....



I'm prompted to do some digging with this one.

I would love to hear the results of your research. I'd join you in your spadework were it not for so many other calls on my time just now.

But your mention of evaporation has made me wonder just how permeable snail shells are...

I took a photo of this little darling not so very long ago just moments after sunrise in my garden when I noticed that the droplets of water were actually on the inside of the shell, and not the outside, as I first assumed.



And here's our semaphore snail again, just for fun. I think he's trying to hypnotise that nettle flower myself

As for the ability to prophesying predilictions of our far eastern sino-kin using the movements of helical housed crawlers, you wouldn't be suprised to hear me link that activity with the rest of the mystery and magic brigade.

No mystery at all then A very wise man once told me that the power of any secret society lay in the fact that people *believed* there was a secret hidden within. The secret itself was of no relevence and did not even have to exist at all in reality

p.s. Note how the occupants of the Agave have arranged themselves according to size. How do they do it?

A very good question. Most animals have to be able to perceive size for judging depth, and also, if they didn't there'd be no point in fluffing up in threat displays, but I've always wondered why dogs seem to be particularly poor at it considering who they chose to mate and fight with But I will rush for my armour before hearing you reply on that one

So I'm thinking that it's not so much a matter of 'how?' as to 'why?" they do it.

But some of our Pisan snails (Theba pisana) who also prey on the hapless sea radish also group together like this at the end of summer especially when the plants have almost been skeletonised (not at that stage here, but a very nice photo all the same:

Pisan Snail - Theba pisana - Guernsey<br /> 29/4/07 Wildlife Photography @ http://www.wildaboutbritain.co.uk/gallery

(And I guess that gives the ID of snail no.2 ).

Sea radish (Raphanus raphanistrum ssp. maritimus) is the ancestor of our garden radish but the root is too woody to be worth eating. It makes gorgeous mists of yellow all around our low-lying coasts, but some rather odd people wanted to tidy it up, so in the past herbicides were used on it.

But the snails saved the day by all migrating inland to nearby vegetable patches, gardens and greenhouses and the wonderful La Société Guernesiaise supported them by lobbying against the spraying, and so it hasn't been done now for many years.

And that's great because the flowers are good for all kinds of insects, and even a solitary bee called
Andrena agilissima that I've heard isn't found anywhere else in the British Isles, so I'll be looking out for that one next year

Hope to hear you latest findings very soon (or from anyone else who can shed light on these mysteries, of course )

Andestine

[Yashca]

Hello everyone!

I got my key to the land snails of the British Isles for Christmas, so have spent today identifying a series of shells I'd been stockpiling. Turns out I had found Arianta abustorum, Cepaea nemoralis, Oxychilus draparnaudi, and another Oxychilus species that I couldn't ID conclusively from an empty shell. Not bad, thought I. I'll have to get some pictures once the light improves.


A question for everyone. On this website there is a photograph of a snail, meant to be Lymnaea peregra, but it looks much, much more like a Succineidae snail to me. Wondered if anyone thought I was right or not, and, if so, whether I should email and mention it.

Wandering snail - Lymnaea peregra - Natural England

Thanks everyone, good luck with your molluscs!