A red swamp crawfish (left) and white river crawfish side by side.

The red swamp crawfish has a blue-grey pigmented line on the underside of the tail. What other differences can you see between the two types of crawfish?

Carapace differences between the red swamp crawfish and the white river crawfish.

Red Swamp Crawfish

• Procambarus clarkii
• crustacean
• 70 – 80 % of annual catch in Louisiana
• The two halves of the carapace meet to form a thin line down the middle of the back
• Almost always has a blue-grey pigmented line on the underside of the tail
• Mature crawfish have less elongated and more flattened claws
• Darker colored walking legs - usually pink or red
• As adults, always have red pigment on their bodies.  Not always so in juveniles.  
• Females lay eggs any time, but mostly during fall and winter months
• Produce up to twice as many eggs as white river crawfish with an average of about 250 babies per female
• Thrive in habitats flooded early in the fall
• Hatchlings are smaller than white river crawfish
• Prefer swampy habitats
• Usually mature during April – June period
• Most young appear in the September – December period
• Commercially valued in Louisiana
• Thrive in seasonally flooded wetlands
• Native range is northeastern Mexico and the south central United States
• Listed as an invasive species in California, Maryland, Nevada, New York, North Carolina, Ohio, Pennsylvania and Virginia
• Introduced to many nations

White River Crawfish

• Procambarus zonangulus
• crustacean
• 20 – 30 % of annual catch in Louisiana
• A space called an areola separates the sides of the back, forming a gap in the middle
• No pigmented line on the underside of the tail
• Mature crawfish have more elongated and cylindrical claws
• Lighter colored walking legs - usually white or tan
• Never has red pigment on its body - sometimes adults can look pink or purplish
• Females lay eggs only during mid- to late-fall
• Produce fewer and larger eggs than red swamp crawfish with about 130 babies per female, on average
• Thrive in habitats flooded late in the fall
• Hatchlings are larger than red swamp crawfish
• Prefer flooded wetlands with flowing, well-oxygenated water
• Usually mature during March - May period
• All young appear in the September – December period
• Commercially valued in Louisiana
• Thrive in seasonally flooded wetlands
• Native range is Alabama, Louisiana, Mississippi and Texas
• Not listed as an invasive species
• Endemic only to the United States