Why does it matter to you?
This particular species is an intermediate host for the causative fluke (worm) of schistosome dermatitis or more commonly known as "swimmer's itch".
Stagnicola catascopium becomes infected by the miracidia (a larval stage) of the causative fluke, most commonly, by coming in contact with the feces of ducks.
After the miracidia infect the snail they become
cercaria (the second larval stage). The cercaria are
then released into the water.
Photo of skin
with swimmer's itch. Photo from MedlinePlus.
Once the cercaria are in the water, if a person gets
into the water they burrow into the skin. Because
they can't get the nutrients they need the cercaria
die under the skin causing a red, irritated bump
that itches. (Leighton,
2011).