Banff Springs Snail

These aquatic pulmonate gastropod mollusks are approximately the size of unpopped corn kernels. The largest ones are only about one centimetre long, and like all of the Physidae, the shells are sinistral or coiled left-handed. The snails' diet consists of periphyton. The Banff Springs snail was first identified in 1926 in the nine sulphurous hot springs of Sulphur Mountain in Banff National Park, Alberta, Canada, and has been found nowhere else. It is very unusual because it is adapted to life in thermal springs where the water is low in oxygen and high in hydrogen sulfide, an environment too harsh for most animals to survive in. Since its discovery, its range has shrunk to just five of the nine hot springs.