Rusty Crayfish

Rusty Crayfish (RC)

Where are RC from and how did they get here?
RC are native to the Ohio River Basin. They are likely spread through non-resident anglers who transport them to use as bait.

How do I identify RC?
You can distinguish a RC from a native crayfish by the rusty red spots on the middle portions of their bodies. Their claws are usually more robust than native crayfish, and have black tips.
Please contact our Water Program Coordinator if you think you have found RC.

Note the RC's rusty side spots and black claw tips

How do RC affect Wisconsin water bodies?
RC are aggressive, and displace native crayfish. They are “clear cutters,” and cut down aquatic vegetation. This decreases habitat for small fish. They also decrease the density and variety of invertebrates.

What can be done once RC enter a water body?
Intensive trapping and harvesting may lower populations of RC in a water body, but it will not completely eliminate the population. The best method of treatment is prevention. Education to anglers, bait dealers, and the general community will help to ensure RC are not spread to additional water bodies.