Red Swamp Crayfish (Procambarus clarkii)
Red swamp crayfish (Procambarus clarkii) can quickly dominate lakes, ponds, rivers and wetlands. They feed heavily on plants, snails, fish, and amphibians, aggressively competing with native crayfish and other species for food and habitat. They can lead to declines in native crayfish and can carry crayfish fungus plague.
Native to Gulf Coast and Mississippi River drainage to Illinois, they have spread to other U.S. waters probably through the release of live study specimens by teachers and students, by aquarists as pets, and by consumers who purchased them from live food markets. They are widely available in the U.S. through the seafood industry and aquarium trade. While they usually spread along connected waterways, they can crawl for several miles at night and during wet weather. Eradicating red swamp crayfish is nearly impossible because they often dig deep burrows into banks of lakes and rivers. Your actions and your help in reporting new infestations are vital for preventing their spread.
Identify Red Swamp Crayfish
- Found in all types of freshwater ecosystems
- Dig chimney-like burrows into bottoms of lakes, ponds, and rivers
- Look similar to native crayfish, except they are dark red; body up to 5" (12.7 cm) long
What You Can Do
- Learn to recognize red swamp crayfish.
- Contact a retailer for proper handling advice or possible returns.
- Give or Trade with another aquarist, pond owner, or water gardener.
- Donate to a local aquarium society, school, or aquatic business.
- Seal aquatic plants in plastic bags and dispose in the trash.
- Contact a veterinarian or pet retailer for guidance on humane disposal of animals.
Report New Sightings — note exact location; freeze specimens in a sealed plastic bag; and call a Minnesota DNR Invasive Species Specialist (see www.mndnr.gov/invasives/contacts.html), 1-888-MINNDNR or (651) 259-5100; or the MN Sea Grant Program in Duluth, (218) 726-8712.
Know the Rules!
Specimens are needed to confirm sightings, but some jurisdictions prohibit possession and transport of invasive aquatic plants and animals. Contact your local natural resource management agency for instructions. Unauthorized introduction of plants, fish, or invertebrates into the wild is illegal. Protect your property and our waters.