Common Name
SWAMP LYMNAEA

Scientific Name
LYMNAEA STAGNALIS

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Utah Taxonomy

Almost all references to this species in Utah have used the currently accepted name Lymnaea stagnalis. Ingersoll (1876) mentioned its presence in Utah and employed the spelling in common use at the time: "Limnea stagnalis". Chamberlin and Jones (1929) and Chamberlin and Roscoe (1948) listed in Utah not only Lymnaea stagnalis but also Lymnaea lepida, the latter name having since then been placed in synonymy with Lymnaea stagnalis.

The race of this species that occurs in Utah is Lymnaea stagnalis appressa.

Status in Utah

About 11 occurrences that seem to represent fresh material have been reported in Utah. Although Baker (1911, Fig. 9) mapped this species as occurring throughout most or all of Utah, localities believed to have been based on living or fresh (i.e., not subfossil or fossil) material have been reported mainly in north-central Utah (Rich, Cache, Davis, Salt Lake, Tooele, and Utah counties) as well as in southwestern Utah (Garfield County) (see Chamberlin and Jones 1929, who summarized much of the literature concerning this species in Utah).

Abundance of this species in Utah is not well understood. Apparently it was once well known, and possibly common, in Utah Lake, where it seemingly no longer occurs. Jones (1940a) listed 5 specimens from one locality.

While threats to this species in Utah are not known, its apparent disappearance from Utah Lake and perhaps other sites suggests its precarious position in Utah. Certainly there are multiple, serious threats to its habitats, especially in the area where most historically reported localities of this species in Utah are situated: along the Wasatch Front. These threats include the draining of wetlands, dewatering and diversions for agricultural irrigation, development (agricultural, industrial, and residential), and degradation of wetlands through many kinds of pollution including agricultural runoff, industrial effluents, sewage, and mosquito abatement activities.

This species formerly was well known from Utah Lake but is believed no longer to survive there, and it is questionable whether it is extant at certain other historical Utah localities. Thus it is considered to have declined and likely still to be declining in abundance and distribution in this state.

Inventory is needed to ascertain the current status (distribution and abundance) of this species in Utah and should begin with surveys for it at the known historical localities.

Care should be taken to distinguish reports of this species based on prehistoric material (fossils or subfossils) from those based on fresh or living examples that represent historical or extant populations.

Habitats Utilized in Utah

Records of this species in Utah summarized by Chamberlin and Jones (1929) refer to lakes, springs, ditches, and "swamps" (presumably meaning marshes). In their (Chamberlin and Jones 1929) discussion of a Utah race (Lymnaea stagnalis wasatchensis) of this species that is no longer considered to be valid, they wrote: "Examples of this form were found conjugating on rushes just below the water line in an old swamp ...."

Sources:

  • Text modified from: Oliver, George V. and William R. Bosworth III. 1999. Rare, imperiled, and recently extinct or extirpated mollusks of Utah[:] a literature review. Publication number 99-29. Utah Division of Wildlife Resources, Salt Lake City. 230 pp.

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