Potamopyrgus doci is a critically endangered species of fresh water snail native to New Zealand.
This snail has been found in only one location in a spring at the exit of Ruakuri Cave, in the Waitomo Caves, north west of Te Kūiti. This habitat is only a few square metres in size but is within a protected area. However, there is recreational rafting in the cave and agriculture upstream may result in a decline in water quality. Despite this the population trend is regarded as being stable.[1]
In 2013 the Department of Conservation classified Potamopyrgus doci as Nationally Critical under the New Zealand Threat Classification System.[2] The species was judged as meeting the criteria for Nationally Critical threat status as a result of it occupying a total area of less than 1 hectare. It is found only in one location.