Invasive Marbled Crayfish Found for First Time in Ontario

By Staff

August 4th, 2023



Marbled crayfish – an aquatic invasive species that is prohibited in the province – has been found in the Burlington area.

This is the first-time marbled crayfish has been found in the wild in Canada and the Ministry of Natural Resources and Forestry (MNRF) and its partners are working to protect Ontario’s habitats and biodiversity from this invasive species.

Marbled crayfish is one of over 30 regulated invasive species under the Invasive Species Act. As such, it is illegal to import, possess, release, transport, breed/grow, buy or sell, marbled crayfish in Ontario. You can’t even keep them in an aquarium. They may be listed for sale under other names such as marble crayfish, self-cloning crayfish or marmorkrebs.

Marbled crayfish reproduce rapidly – each one can produce hundreds of offspring every time they reproduce.

Marbled crayfish reproduce rapidly – with each one having the ability to produce hundreds of offspring every time they reproduce. It only takes the introduction of one marbled crayfish to start a new population, as they are capable of cloning themselves.

If established, marbled crayfish will have a negative impact on Ontario’s native crayfish populations through competition for food and habitat. Marbled crayfish can rapidly take over an area and replace native crayfish species which are already being impacted in parts of Ontario by the invasive rusty crayfish. Marbled crayfish may also impact Ontario’s biodiversity by feeding on algae, plants, invertebrates, and amphibians and may cause shoreline destabilization and erosion through burrowing activities.

That’s why Ontario is being vigilant and quick in our response. Public reporting can play a key role in finding and reporting invasive species. If you’ve seen marbled crayfish in the wild:

Contact the toll-free Invading Species Hotline at 1-800-563-7711

The links below do not work – we are chasing the Ministry people to get them set up

Or report it online or with your mobile device using EDDMapS

For more information, including what you can do to properly dispose of marbled crayfish, contact MNRF staff at

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