What is Ontario Doing?

To prevent these unwanted invaders from coming into the province, Ontario has regulated the Procambarus genus as prohibited under the Invasive Species Act, 2015. 

Background

White River crayfish are large, aggressive crayfish native to the southeastern US. They present a significant threat to Ontario’s waters and have been reported on Pelee Island in Lake Erie for a number of years, with a newer introduction in-land near Port Severn. Due to the significant distance between these two populations, it is fair to rule out natural range expansion of the species. Thus, it is suspected that the two populations are independent of one another and likely represent separate bait releases.

Range

White River crayfish are native to the US, with a disjunct (separated by the Appalachian Mountains) native range that includes the Atlantic coast and the southeastern states of Texas, Alabama, Louisiana, and Mississippi. 

For an up-to-date distribution of White River crayfish in North America, visit www.EDDMapS.org/distribution. 

Impacts of White River Crayfish

• May act as a vector of spread for diseases to native crayfishes, such as the crayfish fungus plague. 
• By eating large quantities of aquatic vegetation, they reduce spawning and nursery habitat for native fishes. 
• Crayfishes are known to eat fish eggs and larvae, which can lead to decreased populations of desired sport fish. 
• They can quickly dominate lakes, ponds, rivers, and wetlands, causing significant environmental change and damage. 
• By burrowing, they create large, intricate tunnels they can compromise shoreline integrity.  
• Female crayfish can carry between 100-500 fertilized eggs under their tail, which allows the crayfish to spread rapidly. 

How to Identify

• White River crayfish are large and can reach 13 cm in total length.  
• Adult White River crayfish are typically a deep burgundy red. 
• They have a pronounced black V-shaped stripe or wedge on the abdomen (tail portion). 
• Chelae (claws) are narrow and long 
• Their claws and body have tubercles (bumps) that are typically black or white.  
• White River crayfish may be mistaken for other species in the Procambarus genus as well as many native crayfishes, such as calico/papershell crayfish (Faxonius immunis) and virile crayfish (F. virilis).   

What You Can Do

• Learn how to identify White River crayfish and how to prevent accidentally spreading invasive species. 
• If you want to use crayfishes as bait, you may only use them in the waterbody in which they were caught. For more information, check the Ontario Fishing Regulations. 
• If you have any information about the release of invasive species, such as the White River crayfish, into Ontario’s waters, report it immediately to the MNRF TIPS line at 1-877-847-7667 toll-free any time, or contact your local Ministry of Natural Resources and Forestry office (ontario.ca/mnrfoffices) during regular business hours. You can also call Crime Stoppers anonymously at 1-800-222-8477. 
• If you have seen a Red Swamp Crayfish or other invasive species in the wild, please contact the toll-free Invading Species Hotline at 1-800-563-7711 or visit EDDMapS to report a sighting. 

Other Resources

• Ontario Ministry of Natural Resources and Forestry
• Invasive Species Centre

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