Hadopyrgus ngataana

This snail has only been found in one spot: in one pool, in a stream at the entrance of Maitai Cave, in the Maitai River Valley southeast of Nelson. It is one of a group of very small, blind, transparent freshwater snails found in caves or underground streams, especially in Northwest Nelson, and like many of these species has evolved in just one small area. == Taxonomy ==

The tiny (1.7 x 1.2 mm) snail was discovered by Frank Climo in the 1970s, but was considered to be just one form of another subterranean Hadopyrgus snail found in the Nelson area. They scientifically described and named it Hadopyrgus ngataana in 2008; == Conservation status ==

In November 2018 the Department of Conservation classified H. ngataana as Nationally Critical, using the New Zealand Threat Classification System. The species meets the Nationally Critical criteria because it is found in just one location, and occupies a total area of less than 1 hectare. == References ==