Species Profile

Mountain Sucker Milk River populations

Scientific Name: Catostomus platyrhynchus
Taxonomy Group: Fishes
COSEWIC Range: Alberta, Saskatchewan
COSEWIC Assessment Date and Status Change: November 2010
COSEWIC Status: Threatened
COSEWIC Status Criteria: B1ab(iii)+2ab(iii)
COSEWIC Reason for Designation:

This small freshwater fish is limited to the Milk River basin of southern Alberta and Saskatchewan. It has a small area of occupancy and number of locations (8) that make it particularly susceptible to habitat loss and degradation from altered flow regimes and drought that climate change is expected to exacerbate.
COSEWIC History of Status Designation: The species was considered a single unit and designated Not at Risk in April 1991. Split into three populations in November 2010. The "Milk River populations" unit was designated Threatened in November 2010.
SARA Status: Schedule 1, Threatened
Date of Listing (yyyy-mm-dd): 2017-04-13

Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.

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

Image of Mountain Sucker

Mountain Sucker Photo 1

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Description

The Mountain Sucker belongs to the family of suckers that live in the western mountainous regions and western-most Great Plains of North America. Based on genetic and geographic factors, the Mountain Sucker has been separated into three Designatable Units in Canada: 1) the Saskatchewan - Nelson River populations; 2) the Milk River populations; and 3) the Pacific populations. The Mountain Sucker has the following characteristics: A sub-terminal mouth, no teeth and fleshy lips (a trait characteristic of suckers); snout is broad and heavy; eyes are small; the body is elongate, cylindrical and somewhat compressed; a relatively small body, with total lengths averaging between 127 to 152 millimeters. The longest length ever recorded was an Alberta specimen at 232 millimeters; the dorsal colouring is typically dark green to grey or brown. The belly is pale yellow to white; there is a dark green to black lateral band and/or five dorsal blotches of fine black pigment on the sides; and during the spawning season, spawning fish develop an orange to red lateral band and both male and females develop “bumps” (tubercles) on their fins.

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Distribution and Population

The Mountain Sucker is found only in the western United States and Canada, typically at higher elevations, although they are found in lowland and prairie streams as well. In the U.S., it is found in the Green, upper Columbia, Yakima, upper Sacramento and upper Missouri river systems, as well as the Lahontan and Bonneville Basins, and in tributaries of the Colorado River, as far south as Utah. In Canada, it can be found in the Columbia, Fraser, Saskatchewan and upper Missouri River Systems (Milk River). Although locally abundant in some selected areas, the Mountain Sucker is not abundant in most Canadian waters where they are at the northern extent of their range.

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Habitat

Mountain Suckers are considered a cool water species, and are associated with small streams at elevations between 20 to 800 meters above sea level, although they occur occasionally in lakes, reservoirs and large rivers. Flows are moderate. The materials along the bottoms (substrates) of the water body vary, but are typically characterized by gravel or cobble.

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Biology

Spawning occurs in late spring or early summer in riffles of moderate to fast flowing water often adjacent to pools. Spawners use the riffle areas, but return to deeper pools once spawning is complete. No nest is built, and the eggs are scattered over river or stream bottoms. Incubation of the eggs is likely between 8 to 14 days, with the frys’ growth rates variable between streams. Females tend to be larger, and live longer than males. Males live about seven years; females live about nine years.

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Threats

Threats to the Mountain Sucker include habitat loss and degraded habitat quality as a result of agricultural and livestock practices; urbanization and industrial development; water management practices and irrigation; and the introduction of aquatic invasive species. In south-central British Columbia and southern Alberta and Saskatchewan, risks relating to water availability may become an even greater threat under drought and climate change conditions.

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Protection

Federal Protection

The Mountain Sucker, Milk River populations, is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.

Fisheries and Oceans Canada is currently consideration the listing of the Mountain Sucker, Milk River populations as Threatened under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available online at AquaticSpeciesAtRisk.ca or on the SARA Registry at SaraRegistry.gc.ca.

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.

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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.

19 record(s) found.

COSEWIC Status Reports

  • COSEWIC Assessment and Status Report on the Mountain Sucker Catostomus platyrhynchus in Canada (2011-09-09)

    The Mountain Sucker, also commonly known as the Northern Mountain Sucker or the Plains Sucker, is a small (usually < 250 mm fork length) bottom-oriented fish of the western mountainous regions and westernmost Great Plains of North America. The Mountain Sucker has a sub-terminal mouth with characteristic “fleshy bumps” (papillae) on the lips. The body is elongate, cylindrical and somewhat compressed caudally. Molecular genetic data and the distribution of Mountain Suckers among three National Freshwater Biogeographic Zones (NFBZ) identify three designatable units (DU) in Canada (Saskatchewan-Nelson DU, Missouri DU and Pacific DU).

Response Statements

  • Response Statement - Mountain Sucker, Milk River populations (2011-12-08)

    This small freshwater fish is limited to the Milk River basin of southern Alberta and Saskatchewan. It has a small area of occupancy and number of locations (8) that make it particularly susceptible to habitat loss and degradation from altered flow regimes and drought that climate change is expected to exacerbate.

Orders

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2010 - 2011 (2011-09-09)

    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 during the past year assessing the status or reviewing the classification of a total of 92 wildlife species.

Permits and Related Agreements

  • Explanation for issuing permit(#19-PCAA-00013), persuant to the provisions of section 73 of SARA (2019-05-09)

    The objectives of the activities covered by this permit application are to assess potential impacts of flow augmentation on Mountain Sucker (Catostomus platyrhynchus) (Milk River populations) vital rates using a RAMP-Ucrit test and a burst test in a swim tunnel, and to assess the potential impacts of climate change on Mountain Sucker by investigating thermal tolerance using a critical thermal maximum (CTmax) test. The activities authorized by this permit consist of the capture of Mountain Sucker from the waterbodies listed on the permit via electrofishing and seine nets; the handling of Mountain Sucker for the purposes of identification and processing (count, measure, fin clips, photograph, etc.); and, the collection of a lethal sub-sample (an overall maximum 450 Mountain Sucker) from the watersheds listed on this permit to assess biology (metabolic enzyme/protein expression) and ecology (age, growth, life history). With the exception of the lethal sub-sample, all Mountain Sucker captured will be returned alive to the location of capture.
  • Explanation for issuing permit(#19-PCAA-00014), persuant to the provisions of section 73 of SARA (2019-05-09)

    The objectives of the activities covered by this permit application are to determine Mountain Sucker (Catostomus platyrhynchus) (Milk River populations) distribution and develop population estimates in the waterbodies listed on the permit, and characterize habitat at each sampling location. The activities authorized by the permit consist of the capture of Mountain Sucker using seine nets. Creeks will be sampled repeatedly throughout the year in an attempt to recapture fin-clipped Mountain Sucker and develop population estimates. This will require the handling of Mountain Sucker for the purposes of identification and processing (count, measure, fin clips, photograph, etc.). Any Mountain Sucker captured will have a fin clip taken and preserved for genetic analysis. All Mountain Sucker will be returned alive to the water after sampling procedures are completed, with the exception of two specimens that will be retained as voucher specimens from any new populations.
  • Explanation for issuing permit(#19-PCAA-00048 ), persuant to the provisions of section 73 of SARA (2019-07-18)

    The objectives of the activities covered by the permit include determining: 1. Whether Mountain Sucker (Catostomus platyrhynchus) exhibit signs of physiological stress during periods of low flow and increased water temperatures; 2. Whether White Sucker (Catostomus commersonii) are less stressed than Mountain Sucker, and therefore may outcompete Mountain Sucker for resources; and, 3. To quantify the level of threat (e.g., low, med, high) that low flows and high water temperatures pose to Mountain Sucker. The activities authorized by the permit consist of: 1. The capture of Mountain Sucker using seine nets. Sites with full sun and full shade (~4-5 of each) will be sampled in mid to late summer; 2. The handling of Mountain Sucker for the purposes of identification and processing (count, measure, fin clips, photograph, etc.). Any Mountain Sucker captured will have a fin clips taken and preserved for genetic analysis. With the exception of the lethal sub-sample, all Mountain Sucker will be returned alive to the water after sampling procedures are completed; 3. The collection of a lethal sub-sample (an overall maximum of 50 Mountain Sucker from the watersheds listed) to analyze heat shock proteins; and, 4. The transport and possession of preserved tissue samples, and any Mountain Sucker killed incidentally or for vouchering purposes.
  • Explanation for issuing permit(#20-HCAA-01687 ), persuant to the provisions of section 73 of SARA (2020-10-06)

    The project will involve installing four riffles within Battle Creek below the Nashlyn Weir, closest to Consul, Saskatchewan. The purpose of the riffles is to create a riffle-pool sequence that restores fish passage over the weir for the first time in nearly 100 years. Displacement of rip rap below the weir has created a scour hole that fish become stranded in under low flow conditions. Approximately 1000 m3 of class 1, 2, 3, and 4 rock, and approximately 300 m3 of gravel will be cleaned and installed to create a predetermined crest height at a 20:1 downstream slope to ensure favourable fish passage under all flow conditions. Approximately 600 m2 of channel will be isolated during a temporary disruption to create dry conditions for the purpose of installing the riffles. Water will be diverted through the existing Nashlyn diversion canal. Fishes will be rescued from the isolated area. Approximately 600 m2 of fish habitat will be permanently altered by the placement of these four riffles. Additionally, a notch will be cut in the timber weir at the location of the most upstream riffle, and two pre-cast concrete blocks will be placed on either side of this riffle. This will result in a permanent alteration of approximately 12 m2, and will provide fish passage over the Nashlyn Weir. The project is proposed to start on October 1, 2020 and be completed by November 7, 2020. In-stream construction is anticipated to last approximately five days. Distribution habitat for Mountain Sucker (Catostomus platyrhynchus) (Milk River populations) is present in Battle Creek at the proposed project site. Mountain Sucker may be present at the time of construction; however, fish surveys over the past five years have not detected Mountain Sucker at this site.
  • Explanation for issuing permit(#20-PCAA-00019 ), persuant to the provisions of section 73 of SARA (2020-06-12)

    The objectives of the activities covered by the permit include: 1. To conduct a morphometric analysis on Mountain Sucker (Catostomus platyrhynchus) (Milk River populations) collected from the locations listed on the permit; 2. To conduct stable isotope analysis on the fish community in the Milk River and Lee Creek; and, 3. To assess potential impacts of flow augmentation on Mountain Sucker vital rates using a ramp-Ucrit test and a burst test in a swim tunnel. The activities authorized by the permit consist of: 1. The capture of the species listed on the permit from the waterbodies listed on the permit via electrofishing and seine netting; 2. The handling of the species listed on the permit for the purposes of identification and processing (count, measure, fin clips, swim tests, and photograph). Fin clips will be taken from a maximum of 10 each per site (three sites total), of Western Silvery Minnow (Hybognathus argyritis), Rocky Mountain Sculpin (Cottus sp.), and Bull Trout (Salvelinus confluentus) (Saskatchewan - Nelson Rivers populations) (Bull Trout from this point forward). With the exception of a lethal sub-sample (see following condition), all fishes captured will be returned alive to the location of capture; 3. The collection of a lethal sub-sample of the species listed on the permit (a maximum of 360 Mountain Sucker, and a maximum of 15 each of Rocky Mountain Sculpin, Western Silvery Minnow, and Bull Trout) to conduct a stable isotope analysis; and, 4. The transport and storage of preserved tissue samples of the species listed on this permit, and any species listed on this permit killed incidentally or for testing purposes.
  • Explanation for issuing permit(#20-PCAA-00035 ), persuant to the provisions of section 73 of SARA (2020-07-17)

    The objectives of the activities covered by this permit are to conduct fish surveys in the Milk River watershed, Alberta, to monitor the effects of low water levels that have occurred as a result of a failure on the St. Mary Canal, the main water source for the Milk River. Mountain Sucker (Catostomus platyrhynchus) (Milk River populations), Rocky Mountain Sculpin (Cottus sp.) (Eastslope populations), and Western Silvery Minnow (Hybognathus argyritis) may be captured during this work. The activities authorized by this permit consist of: 1. The capture of the species listed above from the Milk River watershed, using a combination of boat electrofishing, backpack electrofishing, beach seining, and minnow trapping. The choice of sampling gear will be dependent on site conditions; 2. The handling of the species listed above for the purposes of identification (count, measure, and photograph). With the exception of vouchers that may be retained to confirm identification, all fishes will be released alive after processing; and, 3. The possession and transport of the species listed on this permit found deceased as a result of low water levels, or killed incidentally as a result of sampling and/or processing, or for vouchering purposes.
  • Explanation for issuing permit(#21-PCAA-00020 ), persuant to the provisions of section 73 of SARA (2021-05-07)

    The objective of the activities covered by the permit is to conduct surveys for Western Silvery Minnow (Hybognathus argyritis) within the Milk River watershed in southern Alberta. Rocky Mountain Sculpin (Cottus sp.) and Mountain Sucker (Catostomus platyrhynchus) (Milk River populations) (Mountain Sucker from this point forward) may also be captured during this work. The activities authorized by the permit consist of: 1. The capture of Western Silvery Minnow, Rocky Mountain Sculpin, and Mountain Sucker, using a seine net, from 17 sample locations listed on the permit; 2. The handling of Western Silvery Minnow, Rocky Mountain Sculpin, and Mountain Sucker for the purposes of identification (count, measure, and photograph). With the exception of vouchers that may be retained to confirm identification, all fishes will be released alive after processing; and, 3. The possession and transport of Western Silvery Minnow, Rocky Mountain Sculpin, and/or Mountain Sucker killed incidentally as a result of sampling, processing, or for vouchering purposes.
  • Explanation for issuing permit(#DFO-17-PCAA-00030), persuant to the provisions of section 73 of SARA (2017-07-24)

    The purpose of the project is to determine Mountain Sucker presence in various watercourses in locations both upstream and downstream of diversion structures. Flow alteration from water control and diversion structures has been identified as one of the primary threats to this species. Confirming where it is located in relation to these structures will lead to the development of best management practices to establish flows necessary to protect its habitat. Sampling will be conducted with a seine net in pools along each creek. Captured Mountain Sucker will be counted, weighed, and their length measured to obtain population statistics for the identified watercourses.
  • Explanation for issuing permit(#DFO-17-PCAA-00031), persuant to the provisions of section 73 of SARA (2017-07-25)

    The purpose of the project is to determine Mountain Sucker presence in various watercourses in the Missouri River watershed and to conduct scientific sampling on individuals collected. This research furthers work completed under previously approved permits and will contribute to long-term monitoring and recovery of this species. Sampling will be conducted using backpack electrofishing, seine, and block nets, targeting known distribution areas and additional waterways for Mountain Sucker to assist in understanding the current distribution of the species. Fishes will be held for length measurement and species identification.
  • Explanation for issuing permit(#DFO-18-HCAA-00654 ), persuant to the provisions of section 73 of SARA (2018-08-17)

    The activity involves bank stabilization at two crossings on Grabum Creek, a tributary to the South Saskatchewan River in Cypress Hills Inter-Provincial Park. Two areas associated with a bridge and concrete ford crossing have become eroded, and to address this issue, it is proposed to isolate the work area, remove debris, place riprap in-stream to stabilize the banks, and to replace any debris that was removed. These activities may result in the capture of, harm to, or harassment of individuals during execution of methods to exclude fish from the work area. Mountain Sucker (Catostomus platyrhynchus) is known to be present in the area.
  • Explanation for issuing permit(#DFO-18-PCAA-00002), persuant to the provisions of section 73 of SARA (2018-03-26)

    The activities authorized by this permit consist of sampling via seine nets in pools to determine Mountain Sucker presence or absence in the Milk River and Swift Current Creek watersheds, as well as salvage activities relating to the Davis and Belanger Creek diversion canals. The Water Security Agency (WSA) owns and operates the Davis Creek and the Belanger Creek diversion canals in southwest Saskatchewan. Mountain Sucker may enter the canals when creek flows are diverted and become stranded as water levels recede. WSA will inspect the canals to locate stranded fishes, capture them, and return them to the Davis and Belanger Creeks, respectively. The activities listed above may result in the capture and handling of Mountain Sucker, as well as some habitat disruption.
  • Explanation for issuing permit(#DFO-18-PCAA-00029), persuant to the provisions of section 73 of SARA (2018-06-25)

    The objective of the activity covered by this permit is to conduct surveys of the Missouri River watershed for Mountain Sucker. Collected information will assist in the recovery of the species and inform management decisions as well as future species assessments by the Committee on the Status of Endangered Wildlife in Canada. These activities will involve the capture of Mountain Sucker using a backpack electrofishing unit, and the handling of Mountain Sucker for the purposes of identification and processing (count, measure, photograph, etc.). With the exception of a small lethal sub-sample, all fishes will be released alive after processing. The collection of a lethal sub-sample will be a maximum of 50 fish per site from the watersheds listed on this permit, for the purposes of studying diet, growth, population genetics, and fecundity. Prior to conducting lethal sampling, a field determination of abundance shall be conducted to ensure that the population can support mortalities. The activities listed above may result in the incidental harm, harassment, or killing of Mountain Sucker, as well as some habitat disruption.
  • Explanation for issuing permit(#DFO-18-PCAA-00039), persuant to the provisions of section 73 of SARA (2018-07-31)

    The purpose of this activity is to conduct electrofishing in approximately 500 m of Davis Creek (Saskatchewan) to document the fish community present above and below the Davis Creek culvert, which is part of a proposed habitat reconnection project. Mountain Sucker (Catostomus platyrhynchus) may be captured incidentally during these surveys.

Consultation Documents

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