Michigan bans marbled crayfish, which reproduces rapidly by genetic cloning
(5/15/2020) - A species of crayfish growing in popularity among aquarium owners has been added to Michigan's list of prohibited species.
The marbled crayfish has a unique ability to reproduce by cloning. The Michigan Department of Natural Resources says females can lay 700 eggs that are genetically identical without fertilization.
The crayfish cannot be processed, introduced, imported, sold or offered for sale in Michigan now that they appear on the state's prohibited list.
No marbled crayfish have been found in the wild around Michigan. However, natural resources officials are concerned that a single marbled crayfish could establish an entire population by itself if released into the Great Lakes.
That would allow the crayfish to dominate food chains in Michigan waterways and crowd out native species.
“Marbled crayfish are believed to originate in the aquarium trade, and as such, they have no documented native range,” said Lucas Nathan, DNR aquatic invasive species coordinator. “In some areas where they have been released in Madagascar and several European countries, they have become established and spread rapidly.”
He said marbled crayfish likely could survive Michigan's climate based on invasions in Europe.
Marbled crayfish get their name from a pattern on their backs. They come in olive, brown, tan, red and blue coloring patterns. Some marbled crayfish look similar to river crayfish that are native to Michigan.
Anyone with a marbled crayfish in their aquarium is required to humanely dispose of it and thoroughly clean their tanks to make sure no eggs or young survive.
“Disposing of marbled crayfish by releasing them into the wild should not be considered," said Nathan. “Marbled crayfish have an extremely high potential for becoming invasive due to their reproductive capacity. Their ability to move across land also increases their risk of spread.”
Anyone who finds a marbled crayfish in the wild should capture it if possible, photograph it, record the location and time, and call the DNR at 517-284-6235.