Lake Lamprey
Entosphenus macrostomus
The lake lamprey, Entosphenus macrostoma, also known as the Vancouver lamprey or Cowichan lamprey, a recent derivative of the Pacific lamprey, is a species of freshwater lamprey endemic to two North American lakes: Lake Cowichan and Mesachie Lake in Vancouver Island, Canada. The lamprey was originally called the Vancouver Island lamprey, until an error in filing shortened it to the Vancouver lamprey.
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Countries
Photo: Wikimedia Commons (CC) via https://en.wikipedia.org/wiki/Lake_lamprey
Taxonomy & Classification
Kingdom
Animalia
Phylum
Chordata
Class
Petromyzonti
Order
Petromyzontiformes
Family
Petromyzontidae
Genus
Entosphenus
Lake Lamprey belongs to the family Petromyzontidae, order Petromyzontiformes, within the Petromyzonti class.
Species Profile
The lake lamprey, Entosphenus macrostoma, also known as the Vancouver lamprey or Cowichan lamprey, a recent derivative of the Pacific lamprey, is a species of freshwater lamprey endemic to two North American lakes: Lake Cowichan and Mesachie Lake in Vancouver Island, Canada. The lamprey was originally called the Vancouver Island lamprey, until an error in filing shortened it to the Vancouver lamprey. The alternate common name of "Cowichan lamprey" was coined and promoted by the species' describer, Dr. Dick Beamish, who originally identified the species in the 1980s.
The Lake Lamprey faces severe population declines primarily due to habitat degradation from dam construction, water diversions, and pollution in Pacific Northwest river systems. Historical overfishing and ongoing habitat fragmentation have further reduced populations, with many spawning runs eliminated or severely diminished.
Key Facts
Habitat & Distribution
The lake lamprey is found only in the Cowichan and Mesachie Lakes on Vancouver Island, and is not migratory. The lamprey lives and spawns in shallow gravel areas and typically remains in the lake rather than venturing up streams. The ammocoetes larvae are found in silt depositions along the shores of both lakes. An estimated 1,000 to 2,000 live in the entirety of the two lakes as adults. Sketch...
Threats
IUCN Red List: Endangered
The Lake Lamprey faces severe population declines primarily due to habitat degradation from dam construction, water diversions, and pollution in Pacific Northwest river systems. Historical overfishing and ongoing habitat fragmentation have further reduced populations, with many spawning runs eliminated or severely diminished.
Dam construction and river modification
Water diversions and flow alterations
Habitat fragmentation
Historical overfishing
Pollution and water quality degradation
Found in 1 Country
Community Sightings
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Sources & Attribution
How to Cite
IUCN: IUCN (2025). The IUCN Red List of Threatened Species. Version 2025-1. Available at: https://www.iucnredlist.org. doi:10.2305/IUCN.UK.2025-1.RLTS
GBIF: GBIF.org (2025). GBIF Home Page. Available at: https://www.gbif.org
This page: SpeciesRadar (2025). Lake Lamprey (Entosphenus macrostomus). SpeciesRadar: Intelligence for Earth's Biodiversity. Available at: https://speciesradar.org/species/lake-lamprey