Species at Risk

Banff Springs Snail

Physella johnsoni

What is the Banff springs snail?


A grouping of Banff springs snails.
The Banff springs snail is especially vulnerable at the beginning of the main tourist season, when human activities pose the greatest threat.
© Parks Canada / M. & L Degner / 2002

The thermal springs found at the Cave and Basin National Historic, and all along Sulphur Mountain, support Banff National Park's most endangered life form: the Banff springs snail.

This fascinating mollusc is found nowhere else on Earth!

Although this species was discovered in 1926, scientists did not begin to study it until 70 years later, in 1996. Much still remains to be learned about the Banff springs snail, which made history in 1997 as the first mollusc to be designated/ listed as threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).


Although the largest snails are about the size of a kernel of corn, the majority are about half that size. It is easiest to spot them when they cling to algae, bacteria, sticks or rocks at the water's surface, where they must go to breathe. The snails have dark eyes and a shell that spirals to the left. (Most snails have shells that spiral to the right ).

A Glimpse of the Precarious Existence of the Sublimatable Organism

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