Western River Lamprey

Western River Lamprey Photo Credit: Mike Hayes, Richard Hays, USGS


  • Species Common Name Western River Lamprey
  • Species Scientific Name Lampetra ayresii
  • Federal Listing Status Species of Concern
  • State Listing Status Sensitive


    Special needs

    In some basins, Western River Lamprey, Western Brook Lamprey, and potentially Pacific Brook Lamprey may function as a species complex that interbreeds. Therefore, access for this anadromous species to the ocean and to the resident Western Brook Lamprey and Pacific Brook Lamprey may be important. May aggregate in high densities. Requires fine gravel beds for spawning. Larvae burrow in fine sediment. Timing of development closely linked to water temperature. Adequate food availability during juvenile stage (marine feeding stage). Migration to ocean may depend on sustained inflow from flooding or snowmelt.

    Limiting factors

    Habitat access (artificial obstructions), water quantity (reduced flows, flow management), water quality, physical habitat (stream and floodplain degradation), and predation by other species.

    Conservation actions

    Education and outreach; improve passage and screening; protect and restore habitat; water conservation; establish Best Management Practices for in-water work; modify non-native angling regulations; pinniped management. See ODFW’s Conservation Plan for Lampreys for strategies.

    Key reference or plan

    Coastal, Columbia, and Snake Conservation Plan for Lampreys in Oregon

    Life History Traits