Red Swamp Crawfish

Media
Photo of a red swamp crawfish or crayfish.
Scientific Name
Procambarus clarkii
Family
Cambaridae (freshwater crayfish) in the order Decapoda (shrimp, crabs, and lobsters)
Description

Adult red swamp crawfish are dark red (nearly black on the carapace) and have a wedge-shaped black stripe on the abdomen. Juveniles are a uniform gray, sometimes overlain by dark wavy lines. The pincers are narrow and long. The carapace is not separated at the middle by a space (areola). The carapace is conspicuously granular (roughened) in adults. The rostrum (pointed, noselike structure between the eyes) has lateral spines or notches near its tip.

Similar species: This crayfish most closely resembles the White River crawfish, which differs most obviously in having an areola. Young of the White River crawfish usually have spots on the carapace.

Common Name Synonyms
Red Swamp Crayfish
Size

Adult length: about 2¼ to 4¾ inches.

Where To Find
Red Swamp Crayfish Distribution Map

Occurs widely in the Lowland Faunal Region of southeastern Missouri — the Bootheel.

The red swamp crawfish is the most abundant large crayfish in many swamps, sloughs, and sluggish ditches of the Bootheel lowlands. It prefers substrates of mud or sand, often where there is plenty of organic debris such as logs, sticks, or water-soaked tree leaves. It generally avoids streams and ditches with strong flow, where it is replaced by the White River crayfish. The red swamp crayfish burrows during periods of drought or cold.

Crayfish are generally omnivores, eating a wide variety of plant and animal materials.

This widely distributed species occurs along the Gulf Coastal Plain from the Florida panhandle west to northeastern Mexico and northward along the Mississippi River to the Missouri Bootheel and nearby sections of Illinois. It has been introduced elsewhere in the country and internationally, where it sometimes becomes a pest.

Life Cycle

In Missouri, reproduction probably occurs primarily in burrows during fall and early winter. Most breeding information about this species is from populations in the state of Louisiana, where it is grown as an aquacultural crop.

Economically, this is the most important crayfish on the continent, with a total harvest from wild and aquacultural sources of more than 50,000 metric tons annually, nearly all from the state of Louisiana. Widely introduced elsewhere, including other countries, it can be a serious invasive pest.

Although, in Missouri, it has potential as an aquacultural crop in the Bootheel, this species is tremendously valuable, ecologically, for its role as a food for various animals living in wetland areas. Many species that prey on it have economic value for humans.

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About Aquatic Invertebrates in Missouri
Missouri's streams, lakes, and other aquatic habitats hold thousands of kinds of invertebrates — worms, freshwater mussels, snails, crayfish, insects, and other animals without backbones. These creatures are vital links in the aquatic food chain, and their presence and numbers tell us a lot about water quality.