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Asian Clam (Corbicula fluminea) - photo by U.S. Geological Survey
Asian Clam
Corbicula fluminea

Bloody Red Shrimp
Hemimysis anomala

Common Yabby
Cherax destructor

Golden Mussel
Limnoperna fortunei

Invasive Snails

Killer Shrimp
Dikerogammarus villosus

Rusty Crayfish
Orconectes rusticus

Spiny and Fishhook Waterfleas
Bythotrephes longimanus & Cercopagis pengoi

Zebra and Quagga Mussels
Dreissena polymorpha & D. bugensis


Invasive InvertebratesInvasive invertebrates consist of crayfish, snails, mussels, clams, waterfleas and mysid. Various species of invertebrates have invaded Ontario’s waters through pathways, including ballast water from ships, recreational and commercial boating, aquarium and water garden trade, live fish food and bait bucket release.

Invasive invertebrates impact our aquatic ecosystems by competing with native species for resources, such as food and habitat and can destroy native fish spawning habitats.

Natural movement of species outside their natural range occurs over long periods of time; however, humans can contribute to the spread of invasive species, such as the rusty crayfish, zebra mussels and spiny waterflea.

You can help prevent the spread of these unwanted species.

  • Learn to identify invasive invertebrate species that are a threat to Ontario
  • Don’t release any live organisms into Ontario lakes, rivers or streams
  • Inspect your boat, trailer and equipment after each use. Remove all plants, animals and mud before moving to a new waterbody
  • Drain water from motor, live well, bilge and transom wells while on land
  • Report all sightings to the Invading Species hotline 1-800-563-7711 or report a sighting online