Nevada Fish & Wildlife Office
Pacific Southwest Region

Elongate Mud Meadows Springsnail
(Pyrgulopsis notidicola)

Class: Gastropoda
Order: Caenogastropoda
Family: Hydrobiidae
Genus: Pyrgulopsis
Species: notidicola
Length: shell height is less than 3 millimeters (mm) [0.2 inch (in)]; shell width is less than 2 mm (0.1 in);
Feed: algae gleaned from the substrate and aquatic vegetation
Habitat: Humboldt County , Nevada; endemic to Soldier Meadow;

Life History:

The elongate Mud Meadow springsnail (Pyrgulopsis notidicola) is a small species with a shell height less than 0.12 inches with fewer than five whorls which is a spiral of growth in the shell. The outer shell of the species is light to dark brown and is darkly pigmented internally. It is a member of the family Hydrobiidae, which consists of approximately 100 species of small freshwater gastropods found in the western United States.


Distribution and Habitat:


This springsnail is endemic to Soldier Meadow, located in Nevada at the northern edge of the western arm of the Black Rock Desert. It occurs entirely on public land managed by the Bureau of Land Management (BLM) as part of the Black Rock Desert-High Rock Canyon-Emigrant Trails National Conservation Area (NCA).

The elongate Mud Meadow springsnail occurs in thermal aquatic habitats in four separate, unnamed spring systems. It occupies two types of habitat, one near the source of springs where temperatures are greater than 113 oF. In these high temperatures, the species is semi-aquatic and not submerged, and restricted to the splash zone on rocks and riparian grasses or wetted areas within 0.4 inch of the water. The other habitat occupied by this snail is downstream from spring sources; here the species becomes submerged, limiting itself to gravel substrate in riffles. This springsnail does not occupy sites with low current velocity or habitats with fine substrates.




In 2002, the Service elevated this springsnail to candidate status primarily because of concerns with the increased recreational use of Soldier Meadow, particularly bathing and camping and associated activities. In the summer of 2001, more than 400 campers were observed in and immediately adjacent to the single spring known to contain the species at that time. During this time period, recreational bathers frequently introduced soap, shampoo, and chlorine bleach into thermal spring pools and outflows, prompting additional concerns for the species and health of aquatic systems throughout Solider Meadow.

In October 2012, the Service determined that the elongate Mud Meadow springsnail no longer met the definition of a candidate species under section 4(a)(1) of the ESA. The present or threatened destruction, modification, or curtailment of its habitat or range (Factor A) from unmanaged and increasing recreational use was the greatest threat to the springsnail when the species was elevated to candidate status in 2002. However, since then, the BLM has issued multiple planning decisions and implemented numerous management actions that have effectively addressed the patterns and intensity of recreational use that threatened this species with extinction.

The elongate Mud Meadow springsnail is also found entirely within the boundaries of designated critical habitat for the federally-listed desert dace (Eremichthys acros). This critical habitat consists of the majority of springs and outflows containing this threatened fish, and is surrounded by a 50-foot riparian buffer. Because this critical habitat has been designated on lands managed by the BLM, any federal actions occurring within the critical habitat boundary must avoid adverse modification or destruction of the essential habitat features contained within this boundary. Activities that maintain or improve critical habitat for the desert dace are generally compatible with, and would likely benefit, the elongate Mud Meadow springsnail.


Actions / Current Information:


  Date Title
  11/28/2012 Federal Register for the Elongate Mud Meadow Springsnail. Read More (.60MB PDF)
  11/28/2012 Frequently Asked Questions for Elongate Mud Meadow Springsnail CNOR. Read More
  11/28/2012 Partners Successful Conservation Efforts Help Springsnail. Read More
  2004 Final The BLM has issued a Record of Decision on the RMP and Final Environmental Impact Statement for the NCA, which encompasses the Soldier Meadow area and addresses many conservation measures.
  May 2004 BLM completed the Soldier Meadows Recreation Management Plan (SMRMP) (BLM 2004, pp. 1-78)
Last updated: April 16, 2014