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Post by Paul on Jul 17, 2005 20:00:44 GMT
I agree with you that the two-tone doesn't make a dimidiata, in fact Bequaert does list them with more variety, the two-tone ones being isolated to a few areas. What is strange is that I agree, they seem to have more slender shells and yet the non-pale ones have more ventricose shells, that do look like my dimidiata! The ones pictured there are not albinos either, they have light pinky, orangey bodies. Unless we are totally wrong about that and a lack of pigment would produce that colour. If you look at the picture it is lacking in yellow. Add a tiny hint of yellow in a paint package and you get the skin colour of mine. Apart from one of my adults which has a slightly darker coloured body. I hope you don't think I am jumping on you, not at all, it's nice to debate it. But I can't find much information on immaculata anywhere. Christabel mentions immaculata here: www.geocities.com/sarkymite/snails/gals/immaculata.htmlThe pictures clearly show a very ventricose shell which is nowt like the pictures listed above. Also, she mentions they have a tendency to lose the outer layer of their shell more easily, which doesn't seem to be the case in the pictures above either. On first inspection, the snails on the link above look like immature panthera but you can see they're not when you compare. But that could explain Bequaert's hypothesis that immaculata may not be a true species. What information do you have regarding immaculata? I am basing my ideas on observations and the few scraps I can find so I'd love to know more about how to identify them. At the moment I am not saying that they are dimidiata particularly, they could turn out to be immaculata. But I just think they are the same whatever they are. You only have to look at fulica to see that there is a massive variety of shell shapes in that species. And Bequaert mentions this as a character for African snails in general. I think he attached more importance to the proportions such as the last whorl being 1/2 of the shell length etc.
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Post by Deleted on Jul 17, 2005 20:55:54 GMT
ok perhaps there is a way to solve this: home.global.co.za/~peabrain/achatina.htmthe site says that immaculata always has a columella which is 'truncated at the base' does dimidiata have this? (i.e. does their columella look similar to in the photo of the upturned snail) i dont have a lot of information on this species except the pictures i have seen, the two websites with descriptions and the personal experience of having them. Ive seen a lot of pictures of immaculata, and know that it can vary greatly. I admit that I don't know much about dimidiata, apart from a few pictures ive seen of them where they mostly looked the same. Since immaculata has more polymorphism and variation than dimidiata, surely anneth's snails are more likely to be the former? so do you think that immaculata and dimidiata are the same thing? kind regards mike
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Post by Paul on Jul 18, 2005 4:38:09 GMT
The columella is truncated and is pink in all of mine. Although the only non-truncated columella I have seen so far is Achatina fulgurata. The dimidiata looking one on that link has black skin so I suspect dimidiata have some variation. I don't think immaculata and dimidiata are the same species, but I think dimidiata may be mistaken for albino immaculata. But here is where it gets really confusing. About immaculata, Bequaert says: "Achatina immaculata Lamarck (1822; without locality). Morch listed it from "Senegal", where no species of Achatina is now known to occur. One of Lamarck's types now at the Geneva Museum, is shown on Ferussac's Plate 127 (1823). According to information supplied by Dr. G. Mermod, this appears to be the East African species later described by Ancey (1894) as Achatina mariei."Also: "It should be noted, however, that both Achatina immaculata Lamarck (1822) and Achatina layardi Pfeiffer (1858) may eventually prove to be only subspecifically separable from A. panthera (Ferussac, 1832). If this were true, the species as a whole would have to be called A.immaculata, Lamarck's name being the oldest of the three. I do not have at present the material nor the time to go into this problem".Now look at that link again. It says: "Achatina immaculata – Lamarck, 1822 (Syn. Achatina panthera – Ferussac, 1822)"clearly stating that panthera and immaculata are synonyms of each other. As for dimidiata, having read through the snippet on them again, there are two different dimidiata. Achatina dimidiata Martens (1889) is mentioned as a probable synonym of Achatina balteata var. infrafusca Martens. It says "...uniformly chestnut-brown; at the limit between the two colors with occasional darker spots." But then it mentions the columella being blueish so that is wrong. As for the other, Achatina dimidiata Smith (1878), nothing is listed. www.gasteropoda.net, a great Italian site has the ones I have as dimidiata. The following pic shows them with exactly the same shell shape as the link you supplied: That just confused the matter even more but whatever species is what, I believe the ones your getting and the ones I have are the same. It now seems more possible to me that they are immaculata, but then Bequaert and the fact that the link you supplied seems to treat immaculata and panthera as synonyms of each other make me wonder. How will we ever resolve all of this?
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Post by natrat84 on Jul 18, 2005 7:31:29 GMT
Paul, Does that mean that all our babies could actually be immaculata? Or have I lost track complately lol Nat
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Post by anjieburdett on Jul 18, 2005 8:42:42 GMT
Don't worry - i have too lol.
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Post by Deleted on Jul 18, 2005 8:52:44 GMT
this wud be so much easier if we had DNA tests and didnt have to rely on 100-year-old identification.
have a look at anneth's picture again, as you can see, the shell is longer than in the picture you just supplied, and each whorl is longer. also, the sutures are relatively deep, something i have never seen in dimidiata (but to be honest not much in immaculata either)
also, dimidiata shells just look different, they seem a much lighter colour despite the brown part, i dont think that could be mistaken for immaculata
kind regards
mike
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Post by anjieburdett on Jul 18, 2005 9:38:03 GMT
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Post by Deleted on Jul 18, 2005 9:51:00 GMT
see, are u convinced now? how can the snails in the 3rd photo be the same as in the second photo. they look more like in the first photo (sorry for being so argumentative ) kind regards mike
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Post by Jenna on Jul 18, 2005 14:05:10 GMT
can u get albino snails and wat are they called?
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Post by Paul on Jul 18, 2005 14:13:30 GMT
But, your saying photos 1 and 2 are both immaculata so you're saying it doesn't look like the immaculata in photo 2, but instead looks like the immaculata in photo 1. So I don't get that. You've not changed my mind yet I don't think shell shape or size of whorls matters as I mentioned earlier. It is about proportion rather than shape. As far as I'm concerned the shells in picture 3 are the same shape as theose listed from Achatinidae which you mentioned as a good example of immaculata shell shape. I do know what you are saying about Anneths being darker and looking slightly different and I'd agree. But I still think it is easily within the bounds of polymorphism. As we discussed earlier, most kept in captivity are descended from 1 or 2 holotypes so differences like that seem minimal to me. The ones listed on Achatinidae.de don't look like Anneths at all and in fact look much more like the ones we have. They really do. By your argument, that would mean the ones on Achatinidae.de and Anneths aren't the same. I go back to my original example about fulica, the shell shapes can be vastly different. The immaculata below has been positively identified, and yet look at the shell shape. It is dimidiata shaped, not long and narrow: Also, check outthe immaculata on: achatina.ru/Photo/Page.Eng/Immac.htmAgain the shell shape is the same as my dimidiata, almost exactly. The babies on Anneth's picture look identical to my dimidiata babies although I suppose that doesn't reveal anything. One thing is that the link you sent to the South African page mentions that it is the only snail with a pink columella in the area (apart from Burtoa spp which is easily distinguishable). Well, if that is true then surely that does reinforce my position about them being the same seeing as they both have pink columella that are truncated. DNA testing would be great but I think it would reveal that a lot of the species are theoretical only. They are so closely related, I think we'd get a shock at how few species there actually are. I don't know any way to solve this really. We don't know of any specific trait that immaculata must have to be sure. With fulica, in 99% of cases, it has a blueish-white columella and parietal wall. We need something similar. I thought the pink columella was the thing because as I mentioned the scarce dimidiata info seems to think they don't have this. Which did make me wonder if in fact we do have a form of immaculata.
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Post by Paul on Jul 18, 2005 14:20:45 GMT
Also, what do you make of the immaculata/panthera synonym thing and also the fact that Lamarck's immaculata turned out to be an East African species? That worries me, we're basing it on a species that in 1950 was updated and dis-regarded as another.
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Post by Deleted on Jul 18, 2005 14:33:02 GMT
im saying that the snail in photo two looks like the snail in photo 1, which is immaculata. and it looks completely different from the dimidiata in photo 3. so youre saying its dimidiata JUST BECAUSE there is a slight two-tone in the final whorl of the shell, and it is very slight, and darkened, and you're saying that although this snail deviates from dimidiata in every other way, and is different to every dimidiata i have ever seen, that it's dimidiata? that is very far-fetched, particularly because many many immaculata also have the two-tone shell, even my old ones did. yes dimidiata shells are the same shape as some immaculata, but there is more variation in immaculata than dimidiata, so therefore anneth's snail is more likely to be immaculata. you see, it is possible for immaculata to have slender shells, but not so much with dimidiata, so its probably immaculata. immaculata and dimidiata babies probably look the same, but many species do when young. many immaculata and dimidiata have similar shaped shells, but that doesnt reveal anything! its true for a lot of species. what do you mean about proportion? if the shell shape or size of whorls doesnt matter then wouldnt all snail identification be a little bit difficult? kind regards mike
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Post by Paul on Jul 18, 2005 14:35:05 GMT
Kendra, you can get albino snails and they are just called albinos. But, there are a few species such as Achatina fulica rodatzi that are albinos but have been stabilised if you like, so they are now considered a standard variation. The albinoism can be shell, body or both.
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Post by Paul on Jul 18, 2005 14:57:31 GMT
No, you're getting mixed up with what I am saying. I am not saying they are one or the other. We don't even know what makes a true immaculata or dimidiata so how could I? I am not saying it deviates from dimidiata in every other way, quite the opposite. In fact, I'm very surprised you think that in light of everything that has been posted!
I am saying that the 2 "types" could in fact be the same type. Not just because of a two-tone shell, because of columella truncation (which is very minute in both "types"), the colour and columella twist. The Parietal wall colour, the body colour and the general proportion of the shell.
By proportion I mean the ratio of related sizes. Bequaert says that size and shape varies massively in all African snails but what doesn't change as much is the proportion. So for example, the shell opening being 1/3 of the overall length of the shell, or the body whorl being 1/2 of the overall length. The two are completely different and Bequaert's method would work for snails of all ages and sizes. If you put great store in size and shape, by that reckoning all the different fulica shapes would be different species.
When you say:
although this snail deviates from dimidiata in every other way, and is different to every dimidiata i have ever seen, that it's dimidiata?
What ways?! So far all you have identified is the shell shape, you think immaculata are less ventricose. I am saying that is not a good enough indicator.
that is very far-fetched, particularly because many many immaculata also have the two-tone shell, even my old ones did. yes dimidiata shells are the same shape as some immaculata, but there is more variation in immaculata than dimidiata, so therefore anneth's snail is more likely to be immaculata. you see, it is possible for immaculata to have slender shells, but not so much with dimidiata, so its probably immaculata.
I'm sorry but I'm a bit upset with this comment. I never said they were one or the other, and from what you said you have very little information regarding identifying either. I'm trying to reason it out based on what various sources say, including Bequaert whom everyone turns to for clarification.
In fact I would say that your comment applies to you, I am basing my idea on various traits and observations while you are basing it on shell shape and possibly skin colour (mentioned earlier). This is my exact point, forget species names, I just think that it is possible that these two "types" are the same species. And so far,especially with the columella attributes listed and the link you provided I think that seems more likely than when I started the thread.
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Post by natrat84 on Jul 18, 2005 15:28:27 GMT
Omg whats happening
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Post by Paul on Jul 18, 2005 15:37:08 GMT
Mike, just realised my post is a little emotive It seems to be one of those days Can you clarify exactly why you think they are different. I think they could be the same because: They both have 2 two-tone shells. The shape of standard immaculata is very similar to the dimidiata I have got, so far the only more slender ones are the ones from Achatinidae.de which look more like mine than Anneths. The ones on Achatinidae.de look very like mine. They both have a pink columellas. The both have twisted columellas. They both have rather unsual columella truncation, very slight and very low down. They are both found mainly in South Africa (only one species has a pink columella in this area according to the link you posted). They both grow to the same size it seems. They are both proportionally similar in terms of shell opening and body whorl. They both have the same light bodies (The immaculata are described as albino. If albinoism causes this body colour then that's understandable) Added to which: Bequaert suggests immaculata may not be a true species, even if the name is given to Lamarck when the sub-species are normalised. The South African link you posted clearly states immaculata is a synonym of panthera. I stated all this in previous posts so your "far-fetched" comment put my nose out of joint a little. I think the above is a reasonable basis for my inquiry, especially given how inaccurate traditional identification methods are for African snails. Bequaert came along and effectively normalised 150 years worth of duplication and mis-identification by qualified malacologists who were pioneers in their field. Reading through Bequaerts work is very like what we are discussing here, and in fact in many cases his work is based on less possible evidence than I have listed. So I think my line of inquiry is justified. The thing is, I've started to change my mind about them being different and I'm saying that in the absence of better info the ones you are getting are probably immaculata. In which case, the ones I have are probably immaculata.
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Arno
Archachatina puylaerti
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Post by Arno on Jul 18, 2005 16:44:06 GMT
Ok,now its my turn to be confused,when you say both of the shells are two-toned.The picture that shows the positively id'd immaculata is clearly not two-toned,nor are the snails on Yuri's page.And haven't the shells of immaculata's a more striped pattern than the dimidiata's?
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Post by Paul on Jul 18, 2005 16:58:45 GMT
Yes you are correct, when I say two-toned I am referring to the one's in question ie. the two-toned possible immaculata and the two-toned possible dimidiata.
Do you see what I mean, I am not questioning the id of the striped immaculata. I just think the dimidiata-looking immaculata could be dimidiata or the dimidiata are actually immaculata.
Actually though, I have seen pictures of supposed dimidiata that are striped also.
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Post by Paul on Jul 18, 2005 17:10:14 GMT
I'm not trying to be an argumentative sod , I just want to get to the bottom of it. Have a look at Fredrik's pictures: groups.yahoo.com/group/cybersnail/files/Fredrik's%20snails/ They show both striped and two-tone dimidiata both with much darker skin than mine (well except for one). I think I'll actually implode my own head thinking about this, lol.
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Arno
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Post by Arno on Jul 19, 2005 5:27:21 GMT
Ok,i have seen the pics,and am still not convinced,lol.The only thing i can think of , if they are the same species, is that young and adult snails look totally different from eachother.Having said that Fredriks adult dimidiata still have the red in them i dont see with immacs.
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Post by Paul on Jul 19, 2005 5:31:38 GMT
So do you really think that the dimidiata-looking immaculata are different to what we thought were dimidiata? Where are the differences you and Mike are seeing? All I can see are the similarities, especially since the article Mike used to make his point mentions all that stuff about the pink columella. It seems like yet another piece of possible evidence.
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Post by Paul on Jul 19, 2005 5:34:54 GMT
With regards to the babies what I have noticed is that the babies are extremely striped. I can only think that this stops as the shell gets bigger and the stripes becomes the darker part. Looking at the early whorls on the adults, you can't see the stripes because the whorls have turned white.
I'll let you know when they are bigger because I'm hoping to see some similarities to the adults emerging soon. They're getting close to the size I think it may be occur at.
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Post by Paul on Jul 19, 2005 5:38:54 GMT
Arno, it's just occurred to me.
If you stand by the fact that there are two species, do you not think it is possible that these dimidiata-looking immaculata could have been misidentified as albino immaculata when in fact they are actually dimidiata?
My stuhlmanni have paler bodies than the those immaculata so I assumed that albino snails would be very white (like those pictures on that canned snails site).
That was my original point before I started considering they were the same species.
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Post by Deleted on Jul 19, 2005 7:38:25 GMT
ok about the mis-identified albino immaculata - well all the immaculata i have seen captive bred have had pale skin, and lots of wild ones probably do have darker skin. but i dont see why they would be mis-identified.
I would be inclined to believe that dimidiata and immaculata are sub-species or different forms of each other, but if so, why would Berquaert not list this in his book?
I'm not sure if immaculata and panthera are the same, because my immaculata juveniles looked incredibly different to my panthera juveniles, but maybe this is just because captive ones do not fully represent what is present in the wild, this is where confusion arises.
Achatina fulica and fulica rodatzii look incredibly different, but they are sub-species, so I do not know.
If we DNA tested panthera, immaculata and dimidiata we might be able to find out some things. Different species also usually have internal characteristics that differ e.g. cepaea hortensis and cepaea nemoralis have slightly different shaped mucus glands.
Fredrik's dimidiata looked interesting, but the boundary between the brown and yellow was still quite visible.
This is all very confusing, and shows how complicated snail identification is. you can get 2 species which look almost exactly the same but are different species, and you can get snails which look completely different but are only forms of each other.
Captive dimidiata and captive immaculata have many similarities, the shell shape, the size, the body colour, the columella. But does this represent the wild snails? I don't think so because all the captive snails were probably bred from a small number of snails from an isolated area. So the 2 wild species could turn out to be completely different.
I don't want to have an argument over this, I just wanted to prove that Anneth's snail was immaculata so I wouldn't be getting something I didn't want. But all the questions in this thread have been very interesting.
I wish I could be a malacologist someday (but I would have to pass GCSE science and i doubt I will)
kind regards
mike
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Post by Paul on Jul 19, 2005 13:13:27 GMT
I know what you mean and what you say is very interesting. Bequaert tackled what he could I suppose but there were well over 160 species I think so he obviously normalised what he could It's a shame none of us have both to compare. Perhaps if we ever get a convention together we can compare and reason it out. At the moment I just think there are more similarities than differences but as you rightly pointed out, vast differences can mean little, and in some cases, small differences can mean everything. I hope we can make progress in these areas, DNA tests are only $1 each. So perhaps we'll have a chance at some point. But, I think we'll be in for a number of shocks, if this is done. I can't help thinking it will re-classify loads of species seeing as there is so much confusion currently and that "true" species are probably "sub-species". One thing I did find out is that Bequeart lists what we've been calling sub-species as variants. I didn't realise the significance until the other day when I was checking out what the acronyms spp, ssp etc meant. And a "var" is different to a "subsp". So marginata, ovum and suturalis aren't even sub-species, they are simply variants. That may explain the panthera/immaculata thing but in my opinion, panthera is much more different to immaculata than dimidiata are
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