Degneri and ventricosa

[apple]

How it´s possible to distinguish degneri from ventricosa?

Thanks.
apple

[sezzy5889]

ventricosa have a purple columella, i don't know what degneri has

[apple]

I have here 2 snails( one of them is that one that I put on the snails for sale thread) that they seem to me both ( deg and ventri) but the columella is pink.

[Deleted]

degneri and ventricosa have purple/red columellas.

basically (i'm being quite vague here) degneri has a lighter brown shell than ventricosa.

[apple]

Hey Paul ( maybe he´ll see this thread) don´t you have an idea about this?

[Paul]

They can both have similar columella colours so you can't really use this. I have been working on an ID thing, it is not yet done by any means but you are welcome to see where I am up to for the purple-lipped Archachatina. It's mainly prep stuff I've been calculating and noting down to help me build some rules:

-------------------------------------------------------------------------------------------------------------------------------
                Max Size.  Whorls  Outline         Sculpture  Body Whorl  Sutures             Lip          Columella Slit
-------------------------------------------------------------------------------------------------------------------------------
Rhodostoma      120mm              Slender (1)     Weak                   Scarcely marginate
Degneri         145mm      7       Ventricose (4)  Weakest    77%                              Flared      Broad in juveniles
Ventricosa      130mm      6½      Ventricose (3)  Strongest                                               Deep in juveniles
Purpurea        <100mm     6-6¾    Slender    (2)  Strong      66%-75%    Very marginate       Not flared  Visible in juveniles
-------------------------------------------------------------------------------------------------------------------------------
V.Strong - Easily felt by touch and seen without magnification

----------------------------------------------------------
Shell (L):Shell (W)         AVG         MIN         MAX
----------------------------------------------------------
Purpurea                    1:0.58      1:0.53      1:0.61
Rhodostoma                  1:0.60      1:0.58      1:0.64
Degneri                     1:0.62      1:0.60      1:0.64
Ventricosa                  1:0.65      1:0.61      1:0.68
----------------------------------------------------------

----------------------------------------------------------
Aperture (L):Aperture (W)   AVG         MIN         MAX
----------------------------------------------------------
Rhodostoma                  1:0.54      1:0.52      1:0.59
Purpurea                    1:0.57      1:0.54      1:0.62
Degneri                     1:0.57      1:0.56      1:0.60
Ventricosa                  1:0.58      1:0.55      1:0.64
----------------------------------------------------------

----------------------------------------------------------
Shell (W):Aperture (W)      AVG         MIN         MAX
----------------------------------------------------------
Rhodostoma                  1:0.53      1:0.51      1:0.56
Ventricosa                  1:0.55      1:0.51      1:0.59
Purpurea                    1:0.55      1:0.52      1:0.59
Degneri                     1:0.57      1:0.55      1:0.59
----------------------------------------------------------

----------------------------------------------------------
Shell (L):Aperture (L)      AVG         MIN         MAX
----------------------------------------------------------
Purpurea                    1:0.56      1:0.49      1:0.58
Rhodostoma                  1:0.59      1:0.55      1:0.64
Degneri                     1:0.62      1:0.59      1:0.65
Ventricosa                  1:0.62      1:0.57      1:0.66
----------------------------------------------------------

[apple]

Thank you for the information.
One of them has 125 mm( and it´s growing, I can see that he´s putting a new shell).The shell is completely brown, but with one or 2 faded and creamy stripes. They are very nice snails. Not relevant for Id but interesting is his body that is dark and very large.
The lip is flare the number of whorls it´s seven.

[Paul]

I would say it is a degneri. Is the shell smooth? It has to be a ventricosa or degneri judging by the size. 7 full whorls sounds like degneri also. Degneri are also very smooth compared to ventricosa. If it is a ventricosa you should be able to feel the texture easily and see it without magnification. Also yours sounds more like degneri being unicolorous whereas ventricosa are usually striped, at least on early whorls.

[apple]

The shell isn´t smooth( this means a lot of things, I guess that you are trying to know if it is completely brown, right?) it has one or 2 faded stripes, but on one and not on the other( maybe some slight variations). The apex is clearer, a lot clearer than the rest of the shell, from the apex until the third whorl the colour is a bit clearer. One of the snails has a pink columella ( well I´m getting really confused ( I have him here near the pc, and he was about to getting out of the shell, but I just gently touched him and he went inside a bit again, and I could see it better), his shell is much more smooth than the other, but I made a mistake about the number of whorls they have both 6 and an half. I really don´t know, maybe I have to take more photos.
The other of 125 mm ( this one has 9 cm of shell) has a purple/redish columella, and some 2 creamy stripes.

[Paul]

If it is quite rough it is not degneri then and the size rules out purpurea. Degneri no doubt have some texture, it won't be like glass but it won't be easily visible. Looking at the pictures in the book both are very similar in pattern and shape. I suspect they are ventricosa from what you just said, perhaps normal ventricosa and not speculatum which are rougher.

[Paul]

The book actually says that degneri are quite a conspicuous snail. The pictures I have a black and white so it is difficult to tell, but for that statement to be included I suspect they are quite reddish-brown, like this:

[Paul]

Oh and I have just found that ventricosa also develop a flared lip. That is one of the main factors that defines their subgenus which is Calachatina. Purpurea on the other hand don't get a lip and they are Megachatinopsis.

Which makes me wonder about my suturalis, they actually don't have a lip and they are wild-caught and probably quite old. Catherine got them as papyracea and although I wish they were I'm not convinced. I haven't found any snail including papyracea that looks quite like these, marginata var. suturalis is the most like it because of the wavey stripes, slightly slender shell, the size of over 90mm, bright pink columella and pink early whorls. I need some normal proven margie babies to compare nepionic whorls so I can see for myself what I need to look for. Most of the time all of the terms used to describe stuff are just words on a page until you get to see some examples which help you understand how they go about applying terms to common traits.

[Arno]

What this Megachatinopsis genus then,first time I see it used......

[apple]

Well, I was only doubting between normal ventricosa and degneri, because these 2 aren´t really A. ventricosa speculatum.
They have the same number of whorls of that snail ( do that snail have 7 whorls?
Well that snail is a bit scuffed, I can´t see well the colour of the apex and on the nearer whorls, but they are very similar.

[apple]

snailwatcher said:

What this Megachatinopsis genus then,first time I see it used......

Maybe some really mega achatinas twice a tiger lol.

[Paul]

Degneri commonly have 7 whorls but it must surely be possible for ventricosa to reach 7 in some cases. All I can say is that they are one of those 2 lol. Not much help in the end but I suspect ventricosa because you mentioned them having texture.

Mike,


Subgenus MEGACHATINOPSIS Bequaert and Clench

Full-grown shell medium-sized (50 to 120mm. long), broadly ovate, elongate ovate, or spindle-shaped, of 5 to 7 whorls, normally dextral, often thin and light. Surface even, nepionic whorls of newly hatched snails finely granulose; later whorls either granulose, coarsely decussate or almost smooth. Outer lip always simple, the edge usually thin and sharp, not at all expanded.

A. camerunensis d'Ailly, 1896.
A. knorrii Jonas, 1839)
A. papyracea Pfeiffer, 1845
A. purpurea Gmelin, 1790
A. siderate Reeve, 1849

[apple]

Oh, I ddin´t knew that the photo will turn so big lol
This one has 9 cm of shell.
He´s the one that has a bit pinkish columella

[apple]

His columella.

[Paul]

Both degneri and ventricosa are supposed to have a very pink, red or orange inside lip and yours has a white/blue inside. Is that the 9 cm one. Check the 125mm one.

Also, the body-whorl doesn't look long enough, compared to the others to be either ventricosa or degneri. The last few whorls look very margie-ish. If the larger one has a blue/white inside lip I'd say it is probably a marginata suturalis.

[apple]

The 125 mm is white blue mostly but with some glances of orange.

[Paul]

By the fact that it contain some orange, I can only think it is an immature degneri.

[apple]

Ok.
Actually was that I was thinking.
They are available for sell on a shop here, as well as Archachatina marginata ovum ( not albino one).

[sezzy5889]

well your shops sell such great species

*starts planning to move to Portugal*

[apple]

LOL ;D
I buy snails and sell snails on that shop, but the shop isn´t mine, or I´m understanding wrong what you mean? My english slang is poor...
You are welcome anyway lol ;D

[sezzy5889]

I meant the shops where you live sell different species as to what they do here