"Green" fulica - why do they change colour?

I have 2 whos shells are going a greeny colour too.
But they're not mature yet, they're not from wc parents and it's not just the last whorl it's the whole shell lol.

They're not the only ones in the tank either so if it was the substrate shouldn't the others be like it too?

I have a couple of fulicas that have greenish colour shells too, but I doubt it's because of the substrate to make their shells change in different colour because my others that live in the same tank have brown / dark colour.

I have no lights for that tank. And these 2 parents are not WC ones. When they were babies, the colour of their shells just look the same as my other non-greenish colour shells fulicas.

What causes the changing colour, I cannot answer that though.

i had some of my fulica shells turn from almost black to green after fitting lamps above the tanks, and i think it was beth who had her snails shells turn a different colour after moving them into a big tank with fitted light

ARGH!! Thank god i found this post! I couldn't remember where it was but I knew i'd seen it

Just noticed the other day that my biggest fulica has turned green!!!! I have 2, they are both the same age (about 7 months old) and captive bred. Did we come to a conclusion as to why this happens? I was quite shocked when I noticed it the other day as his shell has turned a definite green colour! My other is fine as are my suturalis.

Thanks,

Dani x

i asked my biology teacher who says it might have something to do with seaasons in thier original country to help camoflage, but it wouldn't explain why some are and others not, :s

Hi,
very interesting fact, and I saw them on the german website that Gabi indicated, how beautiful they are! I believe it's due to some genetical pre-disposition, elicited perhaps by some environmental factors; but if it wasn't genetic, then all of the fulicas in the same tank would turn green, sooner or later.... and don't be fooled, by the fact that they "become" green, many genetical traits are expressed later in life, or only under particular circumstances!
As we debated in the "International Snail Association" topic, it would be important to recognize and breed apart any interesting mutations, even in the more "common" species. So I would strongly recommend to any owners, to select apart their "greenest" specimen, this would be truly a worthwhile new breed of fulicas, and I would be very happy to get a couple myself, in the future!
As to genetic basis, I believe it's a trait coming from a common, shared ancient genetic pool of Achatinidae; as there is at least another "green" species of the same family, Atopocochlis exarata, from Guinea Gulf (a wonderful species that should be introduced in colture, of course); and there are more scattered, unrelated species, as the well-known green one in the Papuina genus.
And it would be interesting, by resorting to some biological laboratory, to ascertain if this unusual fulica's colour is due "simply" to some symbiotic algae; a notable genetic trait itself, if it's really so!
You can see this "green" member of Achatinidae, at the following link
www.arnobrosi.com/worldafrica.html -->
Fabrizio

i'd say its a genetic throwback, it could skip generations and then suddenly re appear. Its definately an interesting topic though.