Hadopyrgus ngataana

The sea or spring snail

Hadopyrgus ngataana is a snail in the family Tateidae (order Littorinimorpha).

Range and habitat

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. Hadopyrgus ngataana is a tiny, transparent, and critically endangered freshwater snail, found only in a single stream in a cave in New Zealand.

Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.

Diet

Snails move on a single foot and feed with a rasping tongue. Island and spring species rarely recolonise once the site is emptied.

In crisis

In November 2018 the Department of Conservation classified H. Ngataana as Nationally Critical, using the New Zealand Threat Classification System. Because Maitai Cave is a popular recreational area, and the stream the species has evolved in is so small, the population of this critically endangered snail is expected to decline.

Hadopyrgus ngataana is Critically Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.

Sources

Written for this catalog from the English Wikipedia article on Hadopyrgus ngataana, Wikidata item Q21784200. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.