The history of Biomphalaria choanomphala contains a migration of epic proportions, though this long distance travel happened by chance.
Molecular work on the Biomphalaria genus has shown that the group originated in South America, probably between 70 and 100 million years ago.
Then, between 2 and 3 million years ago, an ancestor of B. choanomphala (which was probably quite similar to a species called B. glabrata, which still exists in South America) crossed the Atlantic and colonised Africa.
This remarkable journey was either made:
The odds of this happening more than once are astronomically small, and the Biomphalaria colonisers were fortunate to be hermaphroditic and capable of self-fertilisation, in order to be able to establish themselves on a new continent.
Even today, Biomphalaria are still capable of spreading quickly to new habitats, as they are still able to self-fertilise.
B. choanomphala has also shown itself to be versatile in terms of inhabiting water that has been polluted or suffers from eutrophication. This ecological success unfortunately also means it is something of a pest, surviving and even thriving when other rarer molluscs cannot.
As this snail is the intermediate host of a parasite that causes a potentially deadly and often debilitating disease, schistosomiasis, it is important numbers are kept under control.