The Moapa pebblesnail also known as the Muddy Valley turban snail,

scientific name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''Pyrgulopsis avernalis'', is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of small

freshwater snail Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs ...

with an operculum, an aquatic

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Hydrobiidae. The natural

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

of this species is

spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a ...

s, and it is currently threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

. This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Moapa Valley Moapa Valley is an unincorporated town in Clark County, Nevada, United States. As of the 2010 census, it had a population of 6,924. The valley in which the community lies, also named Moapa Valley, is about long and lies roughly northwest to sou ...

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

and the common name refers to the

Moapa River The Muddy River, formerly known as the Moapa River, is a short river located in Clark County, Nevada, Clark County, in southern Nevada, United States. It is in the Mojave Desert, approximately north of Las Vegas, Nevada, Las Vegas. Geography ...

Description

''Pyrgulopsis avernalis'' is a small snail that has a height of and ovate conical shell. Its differentiated from other ''Pyrgulopsis'' in that its penial filament has a small lobe and large filament with the penial ornament consisting of a small terminal gland, a gland along the outer edge of the penial lobe and a ventral gland.

Genus transfer

When originally described in 1935, it was assigned to the genus ''Fluminicola''. In 1994, it was transferred to the genus ''Pyrgulopsis''.

References

Pyrgulopsis Gastropods described in 1935 Molluscs of the United States Taxonomy articles created by Polbot {{Hydrobiidae-stub