DNR Adds Marbled Crayfish to Prohibited Species List

The Michigan Department of Natural Resources has added another prohibited  invasive species.

(Photo courtesy of Mari-Liis Kometsvia Michigan DNR)

Marbled crayfish, also known as marmorkrebs and virgin crayfish, made the list Thursday, May 14 of prohibited species, meaning they can’t be possessed, introduced, imported, sold or offered for sale as a live organism in Michigan. The animal is popular in aquariums and are about four to five inches long with a streaked or marbled coloration pattern, which is most visible on the back. In the wild, most range in color from olive to brown, but in captivity, colors can include tan, red or blue.

The crayfish reproduces by cloning, meaning a female can lay up to 700 eggs without needing fertilization. Officials say if a single marbled crayfish escaped captivity or was released into open water, it could have the potential of initiating an entire population because it can individually reproduce in large numbers.

There are currently no known marbled crayfish in the wild in Michigan.

Owners of the crayfish can humanely dispose of them using guidelines from the American Veterinary Medical Association. Flushing them down the toilet is not considered humane and doesn’t necessarily kill them. Introducing them to the wild is considered a felony.

Those who suspect they have found a marbled crayfish in the wild should photograph it, record the location and time and report the find to Lucas Nathan, DNR aquatic invasive species coordinator, at (517) 284-6235 or [email protected]. If it is possible to capture the crayfish, place it in a container in the freezer until it can be analyzed.

Native white river crayfish and calico crayfish are somewhat similar in appearance to marbled crayfish. To find information on identifying the marbled crayfish and distinguishing it from native species, visit Michigan.gov/Invasives.