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. 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.

If you are seeking information about a specific fish or fish family, you may want to use the search feature to speed the process.

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.