They are a parasite vector.
Kingfisher or other "fish birds", eat the fish, which has the parasite, and then defacates the parasite to the water where the snail picks it up. Fish then eats snail to complete the process. Not a very detailed explanation, but you get the idea.
Reduce snail numbers, and the consequence is fewer fish parasites.
Last edited by Bruce Condello; 10/17/07 07:45 PM. Reason: I read the initial post, and realized I sounded like an idiot. Probably didn't do much better the second time.
