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Red Swamp Crayfish

(Procambarus clarkii)

Photo of red swamp crayfish

The red swamp crayfish originally inhabited the coastal gulf plain region from the Florida panhandle to Mexico. Now the red swamp crayfish can be found in areas of the southern Mississippi River drainage to Illinois. This species has the ability to tolerate brackish water, unusual for most crayfish. They also have been recorded to have the ability to cross several miles of relatively dry ground and can burrow into the ground during extended dry periods.

Overview

Other names for this animal include:
  • Common names: Red swamp crayfish
  • Scientific names: Procambarus clarkii
Ecological threat:

Red swamp crayfish are omnivorous, feeding on aquatic plants, snails, insects, fish and amphibian eggs and young. They have been found to reduce amphibian populations in California and Spain through direct predation and competition for habitat. Populations have also led to declines in native crayfish species in Europe through competition and because they often carry the crayfish fungus plague.

 Overview map of prohibited classification in WI
Prohibited (red) counties

Classification in Wisconsin: Prohibited

Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40.

Identification

Color: The Red swamp crayfish are dark red in color with raised bright red spots covering the body and claws and a black wedge-shaped stripe on the top of the abdomen. Occasionally, a genetic mutation may turn the body and/or claws blue.

Size: They may vary in length between 2 to 5 inches.

Distribution

See the reported Wisconsin locations of this species on the Aquatic Species Tracking pages.

Do you know of additional populations? Send us a report.

Control

Mechanical: Intensive harvest will not eradicate crayfish, but may help reduce adult populations and minimize some impacts. The best method of control is to prevent the introduction of red swamp crayfish by educating anglers, crayfish trappers, bait dealers, and teachers about the threats posed by red swamp crayfish. Doing so will help reduce the risk of spreading the species to new areas.

Chemical: Although there are chemicals that will kill crayfish, there are no chemicals available to eradicate only red swamp crayfish.

Prevention steps:
  • Inspect and remove aquatic plants, animals, and mud from the boat and equipment before leaving the boat launch.
  • Drain water from your boat and equipment before leaving the boat launch.
  • Throw away unwanted bait in the trash.
  • Spray or rinse your boat and equipment with high pressure and/or hot tap water, especially if moored for more than a day, or, dry your boat and equipment completely for at least 5 days.
  • Do NOT use crayfish as bait. It is against the law in Wisconsin.