The albino-shelled margies have been in the forum lately, with nagualgugu posting nice pictures of a GREVILLEI ( pink apex ) and Polyped mentioning a new coming species "BOETTGERI" ( pink apex and pink columella ).
Well that got me looking and I found this shell which is pretty much PINK all over, especially when you look at it from the aperture side. I had identified it as a GREVILLEI, maybe I should put a few queries ? behind that now.
Yep, I guess it looks a little surreal, but it is a genuine product of nature. Colors are fast but highlighted by the removal of the periostracum. Shell is one of many I got from an old collection belonging to an Italian missionary who worked in west Africa during 1950ies-1970ies.
I've made more images under harsher light conditions. Interesting points : note vestiges of darker banding in early whorls and white color in subsutural ramps.
Also shell is not unique, others exist, though pink color not sooooo extreme.
As Archachatina marginata still exists, so do its various forms. So though the shell in the pic was collected over 50 years ago, in all probability there are similar ones roaming around the forests and farms of west Africa.
Meantime here is another view of that shell, this time from the side.
Wow that's really quite an interesting shell. I have to wonder why it evolved to be pink. What sort of environment would this snail blend into? If it doesn't blend into the environment they why on Earth would it evolve to stand out I wonder? Very very nice though. I'm not generally into pink but that is a gorgeous shell! Thanks for sharing.
The extent of pink color in this shell is indeed extensive and rare, but deep pink is a commonly feature of a number of GALS. Here are a few examples. - Just look at deep rose columella of normal Achatina achatina. - Also Achatina achatina roseolabiata which additionally has an external pink lip extending deep inside the aperture, often combined with a pinkish apex. - What distinguishes Archachatina marginata suturalis from normal marginata ? A dark pink/red spire and columella.
For blending in with the environment don't forget in a snail's normal position all the columella can not be seen and the rest of the visible shell is well camouflaged by the periostracum. Anyway the majority of surface soil in west Africa is not dark brown as we know it in Europe. It is rusty-red.
The soil is called laterite and is so colored because it is rich in iron and aluminium oxides. The presence of these oxides may well be the source by which these terrestrial mollusks are able to adorn their shells with these rich colors. Take a look at this picture of a typical road in west Africa and you will get an idea of the color of laterite. ( Looks like the guys in the photo may have some pushing to do ).
Thanks Coyote for that confirmation as I also believe that soil component can have an important influence on the appearance of snails shells.
Laterite is found in many tropical areas, so it would be interesting to observe what the snail fauna looks like in these areas. There are certainly a number of colorfully shelled tropical snails around !
I also found another pink Archachatina marginata grevillei that looks pretty similar to my one that I posted above :
My friend in Cameroon recently sent me some interesting shells. One of them was this Archachatina marginata cf. grevillei (Pfeiffer, 1860). Its just over 10 cms long and was wild caught in the Meme Division.
If I have yellow snale with pink apex and columella, I have grevillei? I hope, yes:) Also I have snail purpurea, but I could not see their descriptions, only one pictures. And I have other snail, I shure.
My snails: -arch. marginata suturalis(normal, albino, akromelano, silver); -arch marginata ovum(light normal); -arch marginata grevillei; -arch. puylaerti(albino); -arch. egreria(leucistic, dark foot); -arch. candefacta; -arch. SP (imported like purpurea).
Hi Shedara, according to Bequaert (1950), grevillei should have the following features:
Shell: yellowish, no (or only very weak) streaks; columella: rose-pink up to wine-red; inner margin of outer lip: white or bluish-white; apex: in part or totally rose-pink up to wine-red; hight of shell and form: about 105 mm, rather broad.