Species Profile

Lake Winnipeg Physa

Scientific Name: Physa sp.
Other/Previous Names: Lake Winnipeg Physa Snail
Taxonomy Group: Molluscs
Range: Manitoba
Last COSEWIC Assessment: November 2012
Last COSEWIC Designation: Data Deficient
SARA Status: No schedule, No Status

Individuals of this species may be protected under Schedule 1 under another name; for more information see Schedule 1, the A-Z Species List, or if applicable, the Related Species table below.


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Quick Links: | Taxonomy | Photo | Description | Habitat | Biology | National Recovery Program | Documents

Image of Lake Winnipeg Physa

Lake Winnipeg Physa  Photo 1

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Taxonomy

Scientists believe that the Lake Winnipeg Physa Snail is a new species - one that is at risk of disappearing before it has even been given a full scientific name. It belongs to the family Physidae, and is clearly distinct from the three other snails in the same family that also occur in Lake Winnipeg.

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Description

The shell of the Lake Winnipeg Physa Snail is usually less than 11 mm long, globe-shaped, and fragile. The spire (whorls of a spiral shell, excluding the last) is flattened, making the snail appear relatively wide, and the surface of the shell is dull and often pitted. Fresh shells are bluish-grey, and the skin of living snails is light grey and sparsely peppered with black spots.

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Distribution and Population

The Lake Winnipeg Physa Snail has not been formally described yet, so it is not surprising that there is no information published on its distribution. However, it appears to be found only in Lake Winnipeg. Extensive surveys of almost 1000 sites in Manitoba, Ontario, Saskatchewan, North Dakota, and Minnesota, including the adjacent lakes and tributaries of Lake Winnipeg, did not detect the snail anywhere except in Lake Winnipeg. The distribution of the Lake Winnipeg Physa Snail in Lake Winnipeg is quite patchy. It was found at only 5 of 90 stations surveyed in 2001. The disappearance of the snail from two previously known sites suggests a population decline.

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Habitat

The Lake Winnipeg Physa Snail can be found on algae-coated rocks that are submerged just below the surface in open, wave-swept areas close to the shore of the lake. The lake bottom is usually a mixture of sand, gravel, and rocks, or occasionally limestone shingle. The Lake Winnipeg Physa Snail tends to occur only in sites with a higher number of other snail species. The average site where the Lake Winnipeg Physa Snail was found had 6.2 species of snails, while the overall average for sites with snails was 3.9 species. The Lake Winnipeg Physa Snail also is always found with at least one other species of Physa snail. The snail appears to be sensitive to metal contamination - the water at the sites where it was found had significantly lower levels of cadmium, copper, and lead than the sites where it was absent.

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Biology

The Lake Winnipeg Physa Snail feeds on algae. Other species of Physa snail that occur in Lake Winnipeg spend the winter as adults and then reproduce in June and July of the following year. The shells of these snails are fragile and individuals typically do not survive for more than one year in Lake Winnipeg.

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The main threats to the Lake Winnipeg Physa Snail are degradation of the shoreline habitat due to cottage development and recreational use, and pollution of the water from agricultural, municipal, logging, and pulp mill activities near the rivers that drain into Lake Winnipeg. Increased shoreline erosion resulting from water level regulation is an additional concern.

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Documents

PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.

11 record(s) found.

COSEWIC Status Reports

COSEWIC Assessments

Response Statements

  • Response Statements - Lake Winnipeg Physa Snail (2007)

    A response statement is a communications document that identifies how the Minister of the Environment intends to respond to the assessment of a wildlife species by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The document provides a start to the listing and recovery process for those species identified as being at risk, and provides timelines for action to the extent possible.

Orders

  • Order Acknowledging Receipt of the Assessments Done Pursuant to Subsection 23(1) of the Act (2010)

    Her Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, hereby acknowledges receipt, on the making of this Order, of the assessments conducted under subsection 23(1) of the Species at Risk Act by the Committee on the Status of Endangered Wildlife in Canada with respect to the species set out in the annexed schedule.
  • Order Acknowledging Receipt of the Assessments Done Pursuant to Subsection 23(1) of the Act (2005) (2005)

    The Order acknowledges receipt by the Governor in Council of 12 aquatic species done pursuant to subsection 23(1) of the Species at Risk Act (SARA) by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The purpose of SARA is to prevent wildlife species from being extirpated or becoming extinct, to provide for the recovery of wildlife species that are extirpated, endangered or threatened as a result of human activity and to manage species of special concern to prevent them from becoming endangered or threatened.
  • Order Amending Schedule 1 to the Species at Risk Act (2011)

    Her Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, pursuant to section 27 of the Species at Risk Act, hereby makes the annexed Order Amending Schedules 1 to 3 to the Species at Risk Act.
  • Order Amending Schedules 1 to 3 to the Species at Risk Act (2006)

    Her Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, pursuant to section 27 of the Species at Risk Act, hereby makes the annexed Order Amending Schedules 1 to 3 to the Species at Risk Act.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2003 (2003)

    May 2003 Annual Report to the Canadian Endangered Species Conservation Council by the Committee on the Status of Endangered Wildlife in Canada.
  • COSEWIC Annual Report – 2012-2013 (2013)

    Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings in this reporting year (October, 2012 to September 2013) from November 25 to November 30, 2012 and from April 28 to May 3, 2013. During the current reporting period, COSEWIC assessed the status or reviewed the classification of 73 wildlife species. The wildlife species assessment results for the 2012-2013 reporting period include the following: Extinct: 0 Extirpated: 2 Endangered: 28 Threatened: 19 Special Concern: 19 Data Deficient: 4 Not at Risk: 1 Total: 73 Of the 73 wildlife species examined, COSEWIC reviewed the classification of 50 species that had been previously assessed. The review of classification for 26 of those species resulted in a confirmation of the same status as the previous assessment.

Consultation Documents

  • Consultation on Amending the List of Species Under the Species at Risk Act - Central & Arctic Region (2004)

    Your opinion is being sought to assist the government of Canada in making an informed decision on whether to add the Northern Madtom, Pugnose Shiner, Kidneyshell, Round Hickorynut, Lake Winnipeg Physa Snail, Channel Darter, Shortjaw Cisco, and Atlantic Cod (Arctic population) to the Schedule 1 (the List of Wildlife Species at Risk) of the Species at Risk Act (SARA). Your input on the impacts of adding these species to the List is important. This workbook has been developed to give you an opportunity to provide Fisheries and Oceans Canada with your feedback, advice, and other comments regarding adding these species to Schedule 1 of SARA (Schedule 1 identifies which species are legally protected under SARA).
  • Consultation Workbook on the Addition of Four Aquatic Species to the List of Wildlife Species at Risk- Lake Winnipeg Physa snail, Channel darter, Shortjaw cisco, Atlantic Cod (Arctic population) (2004)

    Your opinion is being sought to assist the government of Canada in making an informed decision on whether to add the Lake Winnipeg Physa Snail, Channel Darter, Shortjaw Cisco, and Atlantic Cod (Arctic population) to the Schedule 1 (the List of Wildlife Species at Risk) of the Species at Risk Act (SARA). Your input on the impacts of adding these species to the List is important. This workbook has been developed to give you an opportunity to provide Fisheries and Oceans Canada with your feedback, advice, and other comments regarding adding these species to Schedule 1 of SARA (Schedule 1 identifies which species are legally protected under SARA).