AQUATIC INVASIVE SPECIES ALERT!
Red Swamp Crayfish
*Detected in Michigan*
• Dark red color with bright red raised spots, look like small lobsters
• Elongated claws and bony exoskeleton
• Elongated head with a triangular rostrum
• 2.2 inches – 4.7 inches in length
Habitat: Red swamp crayfish live in a variety of permanent freshwater habitats. Crayfish are crustaceans that burrow deep into the substrate of their habitat and create large mounds of sand and soil called chimneys with a relatively large hole in the center.
Diet: Crayfish feed heavily on snails, fish, amphibians, and plants.
Native Range: Mississippi river drainage and Gulf coast
U.S. Distribution (outside of native range): Established populations in California, Delaware, Maryland, Ohio, Oregon, South Carolina, Utah, Virginia, Washington, and Wisconsin. Introduced but not established in Alaska, Hawaii, Idaho, Illinois, Indiana, Nevada, and New York.
Local Concern: Red swamp crayfish compete aggressively with native crayfish species for food and habitat. Feeding behavior reduces the amount of available habitat for amphibians, invertebrates, and juvenile fish. Burrowing and foraging behavior can also lead to summer cyanobacteria blooms and eutrophic conditions.
Other Names: Louisiana crayfish, crawfish, crawdads. Louisiana “mudbugs”
Potential Means of Introduction: Aquaculture/aquarium trade, classroom/laboratory release, live bait dumping, small chance of introduction through fish stocking events
Report this species to Seth Herbst, MDNR, at email@example.com or 517-284-5841 or at www.misin.msu.edu or download the MISIN app to your smartphone
To view an invasive red swamp crayfish focused YouTube video that was recently produced by the
Michigan Department of Environmental Quality click here