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.
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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Update: June 2012