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Crawfish or Crayfish?
Nature Bulletin No. 405-A   February 6, 1971
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

CRAWFISH OR CRAYFISH
.

Crawfish, or Crayfish? There are heated arguments about which is the correct name. The name crawfish was used in 1817 by Thomas Say, the first American zoologist to study these animals. Crayfish was coined by the English scientist, Thomas Huxley, about 50 years later. In this part of the country they are also commonly called "crawdad", "crabs" or, in the southern part of the state, "mudbugs ". Whatever you prefer to call them, there is hardly an acre of water in Illinois (unless it is the depths of Lake Michigan) or any acre of wet land, where these small freshwater relatives of the lobster are not found. About a hundred species are known in North America, of which a half dozen are abundant in this state.

From head to tail, a crawfish is crowded with a large assortment of appendages with special uses for each. In front are a pair of big saw- toothed pincers for defense and capturing food; then four pairs of walking legs, two with small slender nippers and two without, also used for clinging, digging, handling food, and grooming the body. About the head are three pairs of "feelers" for exploring and warning of danger; a pair of beady black eyes on the ends of moveable stalks; three pairs of "jaw-feet" and three sets of jaws that chew sidewise. The flexible 6- jointed abdomen ends in a flaring tail made up of five hinged scoops used for catapulting the animal, when alarmed, backwards in a smokescreen of mud.

As a rule, mature crawfish mate in winter and, in early spring, the females lay 200 or more shiny black eggs which are glued under her tail. These eggs hatch after a month or two and the young are carried there for another month before they let go of their mother's apron strings. Because the shell will not stretch, a crawfish must shed its shell and grow a bigger one, a dozen or more times before it is fully grown. After each molt, while it is still soft and flabby, it pumps itself up with water so that the new shell will be larger. Called "softshells" or "peelers" then, they are extremely helpless and hide until the new shell hardens. This is when they make the best bait for bass and other game fish. Most crawfish are mature after two years and 6 or 7 years is extreme old age. The length of our native adult ranges from 2 to 5 inches, depending on the species.

Crawfish play an important role in Nature. Feeding on a wide variety of plants and animals, either dead or alive, they are the most efficient scavengers in fresh water. They make a superior food for about half of our fish especially for members of the bass family. The raccoon and the mink like them as much as anything else, and all sorts of water birds prey on them. Even the chimney-builders, that spend most of their time in the cool darkness of their burrows, must come out to eat and be eaten. Too few people realize that crawfish make fine eating: whether in salads like shrimp or lobster, in the famous crawfish bisque of the Creoles, or just boiled with a little seasoning for about 20 minutes. Connoisseurs eat the liver, as well as the meat in the tail, and down South they chant an old rhyme.

Yonder comes a man with a sack on his back -- Got all the crawdads he can pack. "


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