Discover Nature: Colorful and Quirky Crayfish

Jul 8, 2018

Discover nature this week and a creature unique to Missouri's clear Ozark streams. According to the Missouri Department of Conservation the clear, rocky streams of the Ozarks are home to twenty-six species of crayfish.

Anyone who has played in a clear Missouri stream has run across what is most often locally called a crawdad. Missouri children spend countless hours catching them every summer but what they may not know is how unique some of these pinchers truly are.

Eleven of our crayfish species have only limited distribution in neighboring states. Eight have never been found outside of Missouri. This is the case for the belted crayfish, a true Missouri native, as its not been found anywhere else in the world. These freshwater crayfish are relatives to shrimp, crabs and lobsters.

At first glance crayfish look pretty much alike but closer study reveals differences in size, color and proportion. This is related to the diversity of habits crayfish use to find food, reproduce and avoid predators. The belted crayfish is only about two and one-half inches long. It lives in clear, medium-sized creeks and large rivers where its belts across its abdominal segments and midsection help to camouflage it among the rocks. This active species emerges at night to forage.

Among the most common invertebrates in Missouri's waters, crayfish are dense in numbers with as many as twenty animals per square meter in some areas. This is good news because crayfish are critical to the proper functioning of our waterways. They're also an important food source for many popular sportfish. Crayfish serve industry and culture in the form of fishbait and freshwater seafood and are most widely known for their role in traditional Cajun cuisine.