Common Name
PYGMY FOSSARIA

Scientific Name
FOSSARIA PARVA

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Utah Taxonomy

Henderson and Daniels (1916) reported this species in Utah under the name Lymnaea parva.

No subspecies are recognized in this species.

Status in Utah

Four occurrences are known in Utah; however, all of these are historical. Of these 4 localities, 3 are in north-central Utah: extreme eastern Box Elder County (Henderson and Daniels 1916), Davis County (Jones 1940a), and Salt Lake County (Jones 1940a). The fourth Utah locality is in the extreme east-central part of the state: extreme southern Grand County (Chamberlin and Berry 1929).

Although good abundance data are lacking for this species in Utah, it seemingly is (or was) rare. The numbers of specimens collected at the 4 Utah localities were 80 (Henderson and Daniels 1916, all very likely having been dead), 1 (Chamberlin and Berry 1929, Chamberlin and Jones 1929), and 3 and 14 (Jones 1940a). It is quite possible that no living individuals of this species have ever been found in Utah.

Threats to this species in Utah have not been reported. Like many native aquatic mollusks in Utah, threats probably are great and likely include dewatering (e.g., draining, diversion), alteration, and degradation (e.g., pollution) of aquatic habitats. Three of the 4 historical occurrences are in the most heavily developed part of the state, an area where most of the wetlands have been drained or extremely altered and where most of the land has been taken up by agriculture and by urbanization; thus, it is doubtful whether any of these 3 occurrences remain. One historical occurrence ("Union, [Salt Lake County,] Utah") is now part of the Salt Lake City urban area and is almost certainly extirpated. Population trend of this species in Utah is not known.

Inventory is needed to determine whether this species is extant in Utah, whether any of the historical populations still exist, and the extent of distribution and abundance, if the species is extant.

Habitats Utilized in Utah

No useful habitat data have been reported for this species in Utah. Henderson and Daniels (1916) reported: "In the dried-up backwater from the canal ... we found 80 Lymnaea parva Lea ...." The implication is that the specimens were empty shells, perhaps washed to the location where they were found.

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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