The Utah roundmouth snail, also known as the Utah valvata or desert valvata,

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 ...

''Valvata utahensis'', 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 ...

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 a gill and 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 ...

mollusc 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 esti ...

in the family

Valvatidae ''Valvatidae'', the valve snails, is a taxonomic family of very small freshwater snails with an operculum, aquatic gastropod mollusks. Taxonomy The family Valvatidae has no subfamilies (according to the taxonomy of the Gastropoda by Bouche ...

, the valve snails. This species of snail 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

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 ...

. The common name refers to the State of

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

Taxonomy

This species was first described as ''

Valvata sincera ''Valvata sincera'', common name the mossy valvata is a species of small freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Valvatidae ''Valvatidae'', the valve snails, is a taxonomic family of ver ...

var. In botanical nomenclature, variety (abbreviated var.; in la, varietas) is a taxonomic rank below that of species and subspecies, but above that of form. As such, it gets a three-part infraspecific name. It is sometimes recommended that the ...

''utahensis'' by

Richard Ellsworth Call Richard is a male given name. It originates, via Old French, from Old Frankish and is a compound of the words descending from Proto-Germanic ''*rīk-'' 'ruler, leader, king' and ''*hardu-'' 'strong, brave, hardy', and it therefore means 'strong ...

(1856-1917, U.S.A.) in 1884 from specimens collected at Utah Lake, Utah (the type locality). R. E. Call elevated ''Valvata utahensis'' to species level in 1886Call R. E. (1886). "On certain recent, quaternary, and new fresh-water Mollusca". ''

Proceeding Davenport Academy of Natural Sciences In academia and librarianship, conference proceedings is a collection of academic papers published in the context of an academic conference or workshop. Conference proceedings typically contain the contributions made by researchers at the conferen ...

'
5
4
5
plate I
figure 1-3. and this was confirmed also in revision of the genus by Bryant Walker">Walker, B. (March 6, 1902). "A Review of the Carinate Valvatas of the United States". ''The Nautilus'
15
11)
121
��125. There was established a subspecies ''Valvata utahensis horatii'' Baily & Baily, 1951 from pleistocene, but Taylor (1966) stated, that ''Valvata utahensis horatii'' should be a synonym for ''Valvata utahensis''.

Shell description

The

shell of the Utah valvata snail is 4.5 mm high, and 4.5 mm width. The average size of adult Utah valvata snails is 4.32 mm. The shell is turbinate in shape, thin, translucent and shining. It is a yellowish horn color at the apex, white or greenish white below the apex. The shell has four whorl (mollusc)">whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral d ...

which are convex, regularly increasing, minutely striate, the uppermost shouldered, with a single, well-marked carina which becomes obsolete on the body whorl. Turbinate shell form and an incipient carina (keel-shaped ridge) on the dorsal surface of the shell distinguishes ''Valvata utahensis'' from the morphologically similar ''Valvata humeralis''. The spire (mollusc), spire of the shell is obtusely elevated, and the apex is depressed. The suture is well impressed. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

of the shell is circular and slightly angled posteriorly. The lip of the aperture is simple, nearly continuous, and it is appressed to the body whorl. The umbilicus is small and round; it is defined by a more or less obvious angle around the base of the shell. The color of the operculum is light horn. The operculum is corneus, spirally multivolute, slightly produced posteriorly to conform to the shape of the aperture.

Distribution

Fossil distribution

The Utah valvata snail, or at least its closely related ancestors, has been described as ranging widely across the western United States and Canada as far back as the Jurassic Period, 199.6 ± 0.6 to 145.5 ± 4 million years ago. Fossils of the Utah valvata snail are known from Utah to California. The Utah valvata snail was likely present in the ancestral Snake River as it flowed south from Idaho, through Nevada, and into northeastern California. The Snake River escaped to join the Columbia River Basin approximately 2 million years ago. Historically, ''Valvata utahensis'' occurred in Utah Lake of

and in the

Snake River The Snake River is a major river of the greater Pacific Northwest region in the United States. At long, it is the largest tributary of the Columbia River, in turn, the largest North American river that empties into the Pacific Ocean. The Snake ...

of southern

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

.Taylor D. W. (1987). ''Thousand Springs Threatened or Endangered Snails''. Unpublished report submitted to

The Nature Conservancy The Nature Conservancy (TNC) is a global environmental organization headquartered in Arlington, Virginia. it works via affiliates or branches in 79 countries and territories, as well as across every state in the US. Founded in 1951, The Natu ...

. 2 pp. This snail is endemic to the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Lake Idaho image:Snake River view near Twin Falls, Idaho.jpg, The Snake River cutting through the plain leaves many canyons and Canyon#List of gorges, gorges, such as this one near Twin Falls, Idaho The Snake River Plain is a geology, geologic feature ...

region.

Recent distribution

The modern range of the snail extended as far downstream as Grandview ( rkm 783, rm 487). However, recent mollusc surveys throughout Utah revealed no live snails, and the species is believed to be extirpated there. At present, this species occurs in a few springs and mainstem Snake River sites in the Hagerman Valley (rkm 932, rm 579). Additional locations include a few sites immediately upstream and downstream of the Minidoka Dam (rkm 1,086, rm 675), near the

Eagle Rock Eagle Rock may refer to: Entertainment * "Eagle Rock" (song), a hit single in 1971 by Australian band Daddy Cool * "Eagle Rock", a song by Motörhead * Eagle Rock Entertainment, a record label Places * Eagle Rock (formation), in California * Eag ...

dam site (rkm 1,142, rm 709) and below the

American Falls Dam The American Falls Dam is a concrete gravity-type dam located near the town of American Falls, Idaho, on river mile 714.7 of the Snake River. The dam and reservoir are a part of the Minidoka Project on the Snake River Plain and are used primaril ...

downstream to Burley. Recent surveys at

’s "Thousand Springs Preserve" revealed declines in numbers and range of the Utah valvata over a four-year period.Frest T. J. & Johannes E. J. (1992). ''Distribution and Ecology of the Endemic Relict Mollusc Fauna of Idaho TNC’s Thousand Springs Preserve''. Final Report to the Idaho Nature Conservancy, Sun Valley, Idaho. 291 pp. In 1991, colonies of this snail persisted in only two areas at the Thousand Springs Preserve, with a population estimate for each colony at or below 6,000 individuals. The population density varied, but it averaged six individuals per meter² (2.69 ft²). For new localities se
Federal Register, July 16, 2009

Ecology

Habitat

The Utah valvata snail persists in a variety of aquatic habitats, including cold-water springs, spring creeks and tributaries, the mainstem

and associated tributary stream habitats, and reservoirs. It was thought that the snail is specialized on well-oxygenated areas of

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

, mud, or mud-sand substrate, among

stream bed A stream bed or streambed is the bottom of a stream or river (bathymetry) or the physical confine of the normal water flow (Channel (geography), channel). The lateral confines or channel margins are known as the stream Bank (geography), banks ...

s with submergent aquatic vegetation. It was thought to be absent from pure gravel-boulder substrate. '' Chara'', a rooted aquatic plant that concentrates both calcium carbonate (CaCO₃) and

silicon dioxide Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...

(SiO₂), is a common associate of ''Valvata utahensis''. However the species occurs on a variety of substrate types including both fine sediments and more coarse substrates in areas both with and without macrophytes. The species has been collected at a wide range of depths, ranging from less than 1 m to depths greater than 14 m, and at temperatures between . Recent work conducted by the Idaho Department of Fish and Game (IDFG) in the upper Snake River demonstrated that Utah valvata snail presence was positively correlated with water depth up to 5.5 m (up to 18.37 feet) and temperature up to 17.2 °C (up to 63 °F), and Utah valvata snail density was positively correlated with macrophyte (a water plant large enough to be observed with the unaided eye) coverage, water depth, and temperature. Similarly, Hinson (2006) analyzed available data from several studies conducted by the USBR (2001-2004), Idaho Power Company (IPC) (1995-2002), IDFG, Idaho Transportation Department (2003-2004) and others, and demonstrated a positive relationship between Utah valvata snail presence and macrophytes, depth, and fine substrates. One study reported Utah valvata snails in organically enriched fine sediments with a heavy macrophyte community, downstream of an aquaculture facility (rm 588). Survey data and information reported since the time of listing demonstrate that the Utah valvata snail is able to live in reservoirs, which were previously thought to be unsuitable for the species.

Feeding habits

''Valvata utahensis'' is primarily a

detritivore Detritivores (also known as detrivores, detritophages, detritus feeders, or detritus eaters) are heterotrophs that obtain nutrients by consuming detritus (decomposing plant and animal parts as well as feces). There are many kinds of invertebrates, ...

, grazing along the mud surface ingesting

diatoms A diatom (New Latin, Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group com ...

or small plant debris. In habitats with boulders on mud, the snail has been observed grazing diatoms and other periphyton (sessile organisms that live attached to rocky surfaces) and aquatic plants.

Life cycle

Utah roundmouth snail is a hermaphroditic snail.Miller M. P., Weigel D. E., Mock K. E. & Roth B. (2006). "Evidence for an outcrossing reproductive strategy in the hermaphroditic heterobranch gastropod ''Valvata utahensis'' (Valvatidae), with notes on the genetic differentiation of ''V. utahensis'' and ''V. humeralis''". ''

Journal of Molluscan Studies The ''Journal of Molluscan Studies'' is the peer-reviewed scientific journal of the Malacological Society of London, covering research in malacology.

'' 72(4): 397-403. . The Utah valvata snail is univoltine (produces one group of eggs per year) with a lifespan of about 1 year. Reproduction and spawning occur asynchronously between March and October, depending on habitat, with the majority of young spawned between August and October. Emergence of a new cohort follows approximately 2 weeks after oviposition, and senescent snails (i.e., those approximately 374 days old) die shortly after reproduction. The Utah valvata snail has been observed to produce egg masses which contained 3 to 12 developing snails.Lysne S. & Koetsier P. (2006). "The life history of the Utah (desert) valvata, ''Valvata utahensis'', in the Snake River, Idaho". '' Journal of Freshwater Ecology'' 21: 285-291. Egg masses are approximately 1.0 to 1.5 mm in diameter, and young snails are approximately 0.7 mm in size upon emergence.

Interspecific relationships

The occurrence of

trematode Trematoda is a class of flatworms known as flukes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host ...

parasites in the Utah valvata has not been studied. Predators of the Utah valvata snail have not been documented; however, it is assumed that some predation by native and non-native species occurs.

Conservation

This species was listed as endangered on the

United States Fish and Wildlife Service list of endangered species This is a list of the bird and mammal species and subspecies described as endangered by the United States Fish and Wildlife Service. It contains species and subspecies not only in the U.S. and its territories, but also those only found in other par ...

on December 14, 1992. U.S. Fish and Wildlife Service. (December 1995)
''Snake River Aquatic Species Recovery Plan''
Snake River Basin Office, Ecological Services, Boise, Idaho. 92 pp. On July 17, 2009, the Fish and Wildlife Service published a proposal in the Federal Register to remove the species from the list of endangered species stating that the Service now knows that the Utah valvata snail is not limited to areas of cold-water springs or spring outflows; rather, it persists in a variety of aquatic habitats, including cold-water springs, spring creeks and tributaries, the mainstream Snake River and associated tributary stream habitats, and reservoirs influenced by dam operations.U.S. Fish and Wildlife Service (July 16, 2009)

''

Federal Register The ''Federal Register'' (FR or sometimes Fed. Reg.) is the official journal of the federal government of the United States that contains government agency rules, proposed rules, and public notices. It is published every weekday, except on feder ...

'' 74(135). The snail was delisted in 2010.U.S. Fish and Wildlife Service (August 25, 2010)
"Removal of the Utah (Desert) Valvata Snail From the federal list of endangered and threatened wildlife".
''

'': August 25, 2010: 52272-52282. ''Valvata utahensis'' is listed as Vulnerable species in the ''2011

IUCN Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biologi ...

''.

References

This article incorporates public domain text from references and a

public domain The public domain (PD) consists of all the creative work A creative work is a manifestation of creative effort including fine artwork (sculpture, paintings, drawing, sketching, performance art), dance, writing (literature), filmmaking, ...

work of the United States Government A work of the United States government, is defined by the United States copyright law, as "a work prepared by an officer or employee of the United States Government as part of that person's official duties." "A 'work of the United States Governmen ...

from references

External links

Species profile of Utah valvata snail (''Valvata utahensis'') at U.S. Fish & Wildlife Service webpage
{{DEFAULTSORT:Utah Roundmouth Snail Valvatidae Molluscs of the United States Gastropods described in 1884 Taxonomy articles created by Polbot