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An Investigation of a Potential Morphotype Trigger in Two IchthyomyzonSpecies

Northern brook and silver lampreys (Ichthyomyzon fossor and I. unicuspis, respectively) are native to the Great Lakes Basin, and occur in many tributaries infested with the invasive sea lamprey.  Lampricides used to control the sea lamprey are also toxic to these native lampreys, and they have thus been assigned conservation designations by multiple agencies in the Great Lakes Basin.  The silver lamprey, which is parasitic and migratory, is currently considered imperiled or vulnerable in three of the states bordering the Great Lakes or Lake Champlain, and its status is being reviewed by the Committee on the Status of Endangered Wildlife in Canada.  The northern brook lamprey, which resides entirely within streams and is non-parasitic (i.e. nontrophic) as an adult, is critically imperiled in five of the Great Lakes states but recent review of its distribution and abundance should lead to its de-listing in Canada.   The separate classification of silver and northern brook lampreys, however, has recently come into question.  Although they are considerably different as adults (e.g., the silver lamprey is much larger, and has a longer adult life span than the non-parasitic northern brook lamprey), they are morphologically indistinguishable as larvae and are genetically indistinguishable.  This suggests that they may be two different feeding types of the same species, much like the different feeding (e.g., normal and dwarf whitefish) or migratory (e.g., sockeye and kokanee salmon) types of other fish.  This study will examine whether northern brook and silver lampreys breed true or whether they can develop into the alternate morphotype under certain conditions.  We will compare environmental and ecological characteristics among streams inhabited by each species, and then artificially spawn and rear each species in streams with characteristics of the other feeding type to determine if they are able to develop into the alternate type under these conditions.   If silver and northern brook lampreys are a single species, it would decrease the probability of silver lamprey listing where northern brook lamprey populations are secure and would allow control agencies to continue treating sea lamprey-producing streams.  Furthermore, if environmental factors determining adult feeding type were known, it could be possible to rehabilitate endangered populations of one feeding type with the other.

In progress
Start Date
End Date
Fraser NeavePrincipal Investigator
Associated with 1 projects
Todd SteevesResearcher
Associated with 2 projects
Margaret DockerResearcher
Associated with 2 projects
Thomas PrattResearcher
Associated with 2 projects
Rob McLaughlinResearcher
Associated with 1 projects
Great Lakes Fishery Commission $ 140,300.00CADActual

Funding 54 projects for a total of $5,089,137.00
Scope of Study
Field Investigation
Laboratory Investigation
Scale of Phenomena
Natural Ecological Processes
Resource Management
Lake Basin Connecting Channels
Lake Huron
Lake Michigan
Lake Superior
State Province
Annex Numbers
Research & Development
Annex 17
Impact of water quality and AIS on fish and wildlife populations and habitats
  • Annex Numbers
    Annex Numbers
    Research & Development
  • Annex 17
    Annex 17
    Impact of water quality and AIS on fish and wildlife populations and habitats

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