Grassland Crayfish (Prairie Crayfish)

Grassland Crayfish (Prairie Crayfish)

Procambarus gracilis
Cambaridae (freshwater crayfish) in the order Decapoda (shrimp, crabs, and lobsters)

This crayfish is bright red to reddish-brown, without conspicuous blotches or spots. The pincers are short and heavy, and the high, dome-shaped carapace is longer than the abdomen. The carapace is not separated at its middle by a space (areola).

The grassland crayfish superficially resembles the devil crayfish, another burrowing species. The devil crayfish is never a uniform bright red, as are many adult grassland crayfish. Males of the two species are readily separated by the shape of the gonopod tips (nearly straight in the grassland crayfish, strongly curved in the devil crayfish).

Adult length: about 2 to 3 inches.
Habitat and conservation: 
The grassland crayfish occurs widely in grasslands and prairies of northern and western Missouri. It lives in burrows that are often a long distance from any surface water. These are usually 4 but up to 6 feet of more in depth and may or may not have "chimneys" above ground. Most public prairies in Missouri support large populations, but this crayfish is seldom seen by visitors because of its secretive habits.
Crayfish are generally omnivores, eating a wide variety of plant and animal materials.
Distribution in Missouri: 
Mostly found in northern Missouri, north of the Missouri River, but extending along our westernmost counties almost as far south as the Arkansas border. A prairie species, its range barely penetrates into the Ozarks.
Life cycle: 
In late spring and early summer, aggressive and sexual encounters result in dominant breeding pairs inhabiting prime burrowing sites, with one male and one female per burrow. Reproduction apparently occurs over an extended period. Starting in late winter and early spring, females move to open water with their newly hatched young. The young remain in the open water, where they mature over the summer, while the females return to their burrows.
Human connections: 
Most people never see grassland crayfish, except on warm, humid nights when they leave their burrows, or during wet periods when juveniles and occasional adults appear in temporary wetlands, ditches, and stream channels. Protecting our remnant native prairies helps protect this species.
Ecosystem connections: 
Crayfish are an important link in the food chain between plants and other animals, breaking down plant materials that are resistant to decay. Crayfish in turn are an important food for many other animals, and their burrowing helps rainwater to soak deep into the earth.
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