Wild About Illinois Fishes!
Illinois is home to a wide variety of fish species. At present 34 families of fishes are represented in the state's waters. Because so many species exist, the fish exhibit a wide range of habits and characteristics.
The information contained in these pages is Illinois specific as much as possible. Several species are highlighted in the family description section of this web site with a color photograph and life history. These photos are copyright protected. No photographs included within this information may be used on the Internet, in publications or in any other form of media without the written permission of the photographer. All rights reserved. All families are briefly characterized and all Illinois species for each family are listed. If you are unfamiliar with vocabulary terms relating to fishes, you will benefit from reading the vocabulary section before looking up the family and species descriptions. The same is true for fish anatomy.
Fish Fact: The grass carp is the largest member of the minnow family in Illinois and was introduced into the state in the 1970s from China.
Fish Families and Gallery
Vocabulary and Anatomy
- adipose fin - fin located between the dorsal and caudal fins; present on some fishes
- anal fin - fin located on the undersurface usually behind the anus
caudal fin - tail fin
ctenoid scale - scale with a toothed rear edge
cycloid scale - scale with a smooth rear edge
dorsal fin - fin located in the middle of the back; it may be notched or divided
exotic species - a species that is not native to an area
extirpated species - one that has been eliminated from a portion of its range, in this case, Illinois
federally endangered species - any species which is in danger of extinction throughout all or a significant portion of its range
nonnative - exotic species
pectoral fin - one of a pair of fins that are attached just behind the head
pelvic fin - one of a pair of fins on the lower part of the body
spawning - depositing eggs in the water
state endangered species - any species which is in danger of extinction as a breeding species in Illinois
state threatened species - any breeding species which is likely to become a state endangered species within the foreseeable future in Illinois
thoracic - on the breast of the fish
Fish or Fishes? The term "fish" is used when referring to one species of fish, no matter how many individuals are present. The term "fishes" is used when more than one species of fish is referred to.
Fish Fact: Fishes have been found in farm fields and streets after heavy rains, but it does not rain fishes! These fishes swam there from nearby water bodies during high water after the storm and became stranded.
Use this diagram to help you learn the name and location of several fish structures.
Fish Fact: Many fish can change color to match their surroundings by expanding or contracting pigment cells in the skin.
Photographs and References
All photographs included on this Wild about Fishes Web site are copyright protected. None of these photographs may be used on the Internet, in publications or in any other form of media without the written permission of the photographer. All rights reserved.
Burr, B. M. 1997. Illinois Chapter of the American Fisheries Society: Minnows of Illinois continuing education seminar. Monticello, Illinois.
Illinois Department of Natural Resources. 1996. Illinois fisheries resources: trends, problems, solutions. Illinois Department of Natural Resources, Springfield, Illinois. 30 pp.
Illinois Department of Natural Resources. 1989. What fish is this? Illinois Department of Natural Resources, Springfield, Illinois. 44 pp.
Moyle, P. B. and J. J. Cech, Jr. 1982. Fishes: an introduction to ichthyology. Prentice-Hall, Inc., Englewood Cliffs, New Jersey. 593 pp.
Page, L. M. and B. M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston/New York. 432 pp.
Pflieger, W. L. 1975. The fishes of Missouri. Missouri Department of Conservation, Jefferson City, Missouri. 343 pp.