MSU Extension Invasive Species

Identifying crayfish can be difficult, especially when they are being purchased from a wholesaler or local retailer. This brochure highlights Michigan’s regulated crayfish species that are prohibited or restricted from sale due to their invasive potential. 

Crayfish are popular aquarium pets and are used frequently in classrooms. Well-meaning people sometimes release unwanted non-native crayfish into waterbodies, and they become invasive and harmful to our environment. They rapidly reproduce, outcompeting our native species for food and habitat. Some invasive crayfish make deep burrows, causing damage to infrastructure and excessive erosion. It is expensive to manage invasive crayfish once they are found in a waterway and eradicating them is challenging.

If you have an unwanted pet crayfish, do not release it into Michigan waterways. Euthanize crayfish by placing them in a freezer, where they will pass in their rest state or contact a local retailer. Check out the Reduce Invasive Pet and Plant Escapes (RIPPLE) website to learn more and to order printed copies of this brochure.