Red Swamp Crayfish

From the Florida panhandle to Mexico, the red swamp crayfish originally inhabited the coastal gulf plain region. Now the red swamp crayfish can be found in southern Mississippi River drainage areas to Illinois. This species can 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.

Classification in Wisconsin: Prohibited

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 declined native crayfish species in Europe through competition and because they often carry the crayfish fungus plague.

Identification

Color: The Red swamp crayfish are dark red with raised bright red spots covering the body and claws and a black wedge-shaped stripe on the top of the abdomen. A genetic mutation may occasionally turn the body and claw 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? Please send us a report.

Control

Mechanical: Intensive harvest will not eradicate crayfish but may help reduce adult populations and minimize some impacts. The best control method 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, no chemicals are 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 hot tap water, especially if moored for over a day, or dry your boat and equipment entirely for at least five days.
• Do NOT use crayfish as bait. It is against the law in Wisconsin.