Snake River Physa snail (Physa natricina)
Where Listed: WHEREVER FOUND
The Snake River physa snail (Haitia (Physa) natricina) is a freshwater mollusk found in the middle Snake River of southern Idaho. It has an ovoid shell that is amber to brown in color, and has 3 to 3.5 whorls (curls or turns in the shell). The physa can reach a maximum length of about 6.5 millimeters. The Snake River physa is believed to have evolved in the Pliocene to Pleistocene lakes and rivers of northern Utah and southeastern Idaho. While much information exists on the family Physidae, very little is known about the biology or ecology of this species. It is believed to be confined to the Snake River, inhabiting areas of swift current on sand to boulder-sized substrate. In 1995, the Service reported the known modern range of the species to be from Grandview, Idaho (RM 487) to the Hagerman Reach of the Snake River (RM 573). More recent investigations have shown this species to occur outside of this historic range to as far downstream as Ontario, Oregon (RM 368), with another population known to occur downstream of Minidoka Dam (RM 675). While the speciesí current range is estimated to be over 300 river miles, the snail has been recorded in only 5% of over 1,000 samples collected within this area, and it has never been found in high densities. The speciesí status is uncertain within the current known range, but portions of the middle Snake River (e.g., Milner Reservoir, RM 663 to Lower Salmon Falls Reservoir, RM 572) are of questionable habitat value given current water quality and water use issues. In addition, the sampling in this reach has been limited. Very few live specimens have been recovered from reservoirs which have been extensively sampled. The recovery area for the species extends from Snake River mile 553 to Snake River mile 675. It is currently listed as an Endangered species.
- States/US Territories in which the Snake River Physa snail, Wherever found is known to or is believed to occur: Idaho
- US Counties in which the Snake River Physa snail, Wherever found is known to or is believed to occur: View All
- USFWS Refuges in which the Snake River Physa snail, Wherever found is known to occur:
Minidoka National Wildlife Refuge
|Status||Date Listed||Lead Region||Where Listed|
|1992-12-14||Pacific Region (Region 1)||Wherever found|
» Federal Register Documents
|Date||Title||Plan Action Status||Plan Status|
|1995-11-26||Snake River Aquatic Species Recovery Plan||View Implementation Progress||Final|
|Date||Citation Page||Title||Document Type|
|2012-03-06||77 FR 13248 13251||5-Year Status Reviews of 46 Species in Idaho, Oregon, Washington, Nevada, Montana, Hawaii, Guam, and the Northern Mariana Islands:Notice of initiation of reviews; request for information.||
|2014-05-23||Snake River Physa 5-year review|
» Critical Habitat
No critical habitat rules have been published for the Snake River Physa snail.
» Conservation Plans
No conservation plans have been created for Snake River Physa snail.
» Life History
No Life History information has been entered into this system for this species.
» Other Resources
NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.
ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.
FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.