MSU Extension Invasive Species

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

Exotic fish are popular pets in aquariums and water gardens. Well-meaning people sometimes release unwanted pet fish into waterbodies thinking they are doing the right thing, but they can become invasive and detrimental to our environment. Some outcompete our native fish for food and habitat. Released pets can also introduce harmful pathogens and diseases to our native wildlife. Additionally, it is not humane to release unwanted fish in Michigan waterways. Pet fish may lack the necessary skills to survive in the wild or may not be able to tolerate Michigan’s climate.

If you have an unwanted pet fish, do not release it into Michigan waterways. Give or trade with a local retailer or other hobbyist. Check out the Reduce Invasive Pet and Plant Escapes (RIPPLE) website to learn more and to order printed copies of this brochure.