snail intelligence and memory

[dio23]

I was searching the internet for information on the intelligence, memory and social skills of snails. Common land snails and african giant snails are very similar I guess, since they are closely related.
When watching my snails, I could make some observations, but it's hard to tell if I understand correctly. For example, they do seem to "remember" where their home is, but maybe it's just that they can smell certain chemicals they secreted?
If anyone has any concrete info on this subject, I would be very interested.
So far, I found an article saying that they recognize the broken shells of their dead colleagues and leave the scene quickly.
It's also thought-provoking that snails have such an extraordinary mating behaviour, much more intimate than some humans. What is the need for this? Could it be that they do have some sort of emotion?
So many questions... Any answers? Thanks.

[number2301]

Sorry I can't help but I'd love to see some answers to this as its really interesting!

[tanja]

In Germany was an article about the flood on the oder (a river). All snails crept two days before the flood com on the trees and the walls of the houses.

My snails remember, where their food is. If I put the cup with the food on another place, they search first on the old place.

And my snails accustom to my hand - first some of them are often shy. If I handle them regulary, they would be more trustingly. It depends on the species, fulicas and retis are very trusting from the hatching.

Another article in german says that snails count their eggs. So they know, how many eggs were layed for the reason that they not go for broke when they lay to many.

I hope it would be comprehendible, I always look for the right words on leo dictionary.
:-)

[Carolyne]

Snails have memory (Its remember a food who ate, eat it immediately, do not analyze it before ) but intelligence I don't know.

[dio23]

They seem to have a vague memory of where things are. They know that there is a stick somewhere around, so they stick out their eyes as far as they can to find it.
Any more info on intelligence? I'd be really interested!

[batoo]

I have cover on my box with snails when I remove cover the snails are still hiding their eyes because of cover:) but cover isn't there anymore. They have a good memory. (Achatina fulica&Iredalei).

[coyote]

Snails can smell calcium, apparently. See this page and scroll down to "The Smell of Calcium," where he describes an experiment he conducted to determine if snails can smell calcium. If they can smell calcium, it stand to reason that they can smell many other things vital to their survival as well.

At that link you can also read about the mating behavior of H. aspersa as well.

[coyote]

I thought I was getting nowhere googling helix aspersa intelligence (lol), until I found this:

"Terrestrial gastropods have an ability to learn, i.e., they display "intelligence." The malacologist William Healey Dall (1881) once wrote a serious account about a child who had pet snails (apparently Neohelix albolabris or a related secies) that "recognized" her voice and distinguished it from others. Garth and Mitchell (1926) used physical stimuli (heat, light, electricity) to train specimens of a land snail to "run" a T maze to a comfortable cool, dark place. Humphrey ( 1930) showed that the withdrawal response of N. albolabris disappeared upon repetition of a mechanical stimulus; i.e., the snail became habituated. Habituation disappeared after an appropriate rest. An unfavorable olfactory cue was used to train the slug Limax maximus to avoid normally palatable foods (Gelperin 1975). Sahley et al. (1990) showed that an initially aversive odor to L. maximus can be made attractive if that odor were repeatedly paired with an attractive chemostimulant. According to Carew and Sahley (1986), the higher-order features of learning seen in L. maximus rival that observed in such star performers in the vertebrate laboratory as pigeons, rats, and rabbits!"

LINK, scroll down to "Learning and Intelligence."

[manxminx]

Fascinating thread and some excellent links, thanx

I watch my (garden dwelling) Helixs every night and yes, they definitely show signs of inteligence. I only had to show them once where I put their food, now they go straight there in the evening and wait for me to give them breakfast.

They are also aware of their environment and have got used to me handling them - the older ones preferring it more than the younger ones.

Ali.

[phantomsnail]

about a 2 years ago in the spring, i released 2 WC Roman snails (helix pomatia?) back where they originally came from. A year later as winter was drawing in, i was out in the front garden one morning and found first one then both the snails. I found this extraordinary as I released them about a mile away from my house. I was sure they were the same snails and compared their shell markings 2 that of previous pics i had of them. They were definately the same snails. I kep[t them in over winter and released them again the following spring. Haven't seen them since! I am still amazed they found their way back home!

[Rachel]

snails have strong homing instinct and have been proven to manage to return from (i think) 5 miles away, quite a distance for a human never mind a small slow snail. they rule!

[coyote]

I wonder how long it would take a snail to travel 5 miles?

[sandie]

It seems that we underestimate our Snails' intelligence too easily. My Snails constantly amaze me with their ability to recognise my voice. They do "know" me, I am certain of it.

Quite frankly, they are among the most fascinating pets I have ever kept. (I won't say "owned", because we do not "own" our Snails, we just "keep" and "care" for them.)

I think they realise that they are on to a good thing!

[Deleted]

Jul 28, 2008 23:04:54 GMT sandie said:

My Snails constantly amaze me with their ability to recognise my voice.

I don't think snails can actually hear at all...

[natasa]

Jul 28, 2008 23:04:54 GMT sandie said:

(I won't say "owned", because we do not "own" our Snails, we just "keep" and "care" for them.)

I agree with you! Noone can own a pet. I think we shouldn't buy them from pet shops, too. They are living animals, not tools or something...

[brgwnth]

then why would you keep them, natasa?

[coyote]

In San Francisco, the law says that pets are "companion animals," not "pets," and the people they live with are not "owners," but "guardians." Pets used to be regarded as property, and San Francisco is trying to change that.

[snailysnail]

but what happens when someone dies, what happens to their companion dog, say? you can't just release it or say they were just a guardian of it and it doesn't need them anymore?

sorry if the answer is obvious, im just confused as to how it works!

anna x

[kanin]

For many years I and others done some research on the behavior of Helix Pomatias in a native (wild) colony in skåne in sweden. We marked the snails with a ID number, ofcourse in an unharmful way, and returned after rain to collect as many of them we could find in order to weigh and meausure their size. We also looked for empty shells and if we could we established cause of death(in most cases eaten by hedgehogs or crows).

In the log I also wrote if there where any special circumstances each time their where found, if they where found in company with other snails etc.
This part I may think could be interesting. Some individuals where often found together, interacting or in the vicinty of eachother.
So regarding the snails social skills some seem to prefeer specific individuals before other and even if they where moving over quite large areas some seemed to stick together as "friends" if snails are capable of that relationship.

In my Pomatia tank, where I also keep cepea hortensis and cepea nemoralis, the pomatias seem to when facing unfavorable conditions dig common underground-dwellings. I've seen up to five indivudals use the same "cave" often the cepeas join the pomatias in theese dwellings. I've heard that a species of slug(Arion lusitanicus) also dig common dwellings. there have been a lot of reaserch on this species in sweden as they are considered an agricultural pest. I actually heard this as an sugestion to use TNT to blow up this dwellings as they sometimes house up to a thousand individuals.

What I wanted to say with the dwelling statement is that they obviously prefeer the company of other snails in the dwelling otherwise they would probably dig separate holes.
If thats true for the Arion lusitanicus I'm not sure because they tend to to keep together but as soon as they begin to starve they turn to canibalism, wich could be why they gather in such numbers to survive the draught by eating the weakest individuals. They are actually called Mördarsnigel(Murder-slug) in sweden.

[kanin]

And, Sandie, I believe they can recognize your voice. But not the voice itself as they can't "hear" but the vibrations of your voice as they are very sensitive to vibrations and most probably can feel the vibrations of the soundwave, if their out of their shell.

[coyote]

Aug 6, 2008 9:30:32 GMT snailysnail said:

but what happens when someone dies, what happens to their companion dog, say? you can't just release it or say they were just a guardian of it and it doesn't need them anymore?

sorry if the answer is obvious, im just confused as to how it works!

anna x

Well, it depends on what arrangements the people have made for their pets. Some people ask friends or relatives to take care of their pets. Some people create a trust for their pets, setting aside money dedicated to the on-going expenses of food and medical care.

If someone hasn't made any arrangements for their pets before they pass on, the City of San Francisco will take custody of the animal and put it up for adoption. San Francisco is a no-kill city, meaning that by law no adoptable animal will be euthanized unless it becomes gravely ill. The city animal shelter or the private S.F. SPCA will house the animal until it gets adopted, no matter how long that takes.

The SPCA had a cat that lived at the shelter for 2 years before getting adopted. And they do not live in cages, either -- they live in regular rooms with chairs and furniture just like in a person's home! Check it out: www.sfspca.org/adoption/maddies.shtml

Most animals do not stay in the shelter that long, though. Most get adopted within a month.

[Joedy]

When I first brought home snails (helix aspersa) at all, I brought home a female who I found laying eggs. I didn't have much knowledge on breeding or things of the like with snails then, so I kept her and her brood. I also found a smaller, darker mature snail, who I also kept. They lived in a large Tupperware box with dirt while the eggs were in a separate Tupperware, and I noticed the larger one (I named her Leslie) could not stand the other snail. It was odd, because I would put a small piece of carrot as a treat to their Romain diet, and I found out that Leslie was crazy about carrots. The part that has to do with behavior, is the fact that when the other snail would come to share the carrot, she would literally attack it. She would crawl over, and seemingly being aggressive, using her scraper against this snail's body (even though it probably didn't hurt the thing). This sent some sort of trigger I think, because it bubbled up and sealed itself up. Leslie enjoyed the carrot alone.

Now, I figured then maybe that they didn't like company. But when I returned to the same place that I found her and the other snail, I brought home three other mature snails, who she had no problem with. It was weirdly consistent as well, because she and the other snail were always far apart, though they would both huddle up with other snails.


Maybe I'm just making all this up in my head or something, but I do notice that a lot of my snails huddle up in the same groups as well. So personally I think they do have some sort of social understanding.