| Specimen ID | State | County | Locality | Year | HUC Number | Drainage Name | Status |
| 1692929 | IL | Cook | 1 mi N Calumet City | 1982 | 04040001 | Little Calumet-Galien | unknown |
| 33728 | IL | | Lake Michigan | 1991 | 04190000 | Lake Michigan | established |
| 33625 | IL | | Lake Michigan | 1979 | 04190000 | Lake Michigan | established |
| 33626 | IL | | Lake Michigan | 1945 | 04190000 | Lake Michigan | established |
| 33574 | IL | | Lake Michigan | 1923 | 04190000 | Lake Michigan | established |
| 613765 | IL | Cook | Lake Michigan: Chicago; 11.8 mi. W of William E. Dever Crib Lt., 14.3 mi. E of shore (beach) | 1983 | 04190000 | Lake Michigan | established |
| 1456468 | IL | Cook | Lake Michigan, 12th Street and Lake Michigan | 1964 | 04190000 | Lake Michigan | established |
| 1692527 | IL | Cook | Jackson Park | 1960 | 04190000 | Lake Michigan | unknown |
| 1692553 | IL | Cook | 30 mi ENE Chicago River | 1962 | 04190000 | Lake Michigan | unknown |
| 1692638 | IL | Lake | Highland Park | 1964 | 04190000 | Lake Michigan | unknown |
| 1692639 | IL | Lake | North Chicago | 1964 | 04190000 | Lake Michigan | unknown |
| 1692640 | IL | Lake | Waukegan Harbor | 1964 | 04190000 | Lake Michigan | unknown |
| 1692641 | IL | Lake | Zion, N edge Illinois Beach State Park | 1964 | 04190000 | Lake Michigan | unknown |
| 1692642 | IL | Lake | Winthrop Harbor | 1964 | 04190000 | Lake Michigan | unknown |
| 1692643 | IL | Cook | Evanston | 1964 | 04190000 | Lake Michigan | unknown |
| 1692735 | IL | Cook | Evanston | 1966 | 04190000 | Lake Michigan | unknown |
| 1692644 | IL | Cook | Jackson Park harbor & beach | 1964 | 04190000 | Lake Michigan | unknown |
| 1692734 | IL | Lake | 2 mi N Waukegan | 1966 | 04190000 | Lake Michigan | unknown |
| 1692791 | IL | Lake | 6 mi NE Waukegan | 1967 | 04190000 | Lake Michigan | unknown |
| 1692836 | IL | Cook | Winnetka, Lloyd Park Beach | 1968 | 04190000 | Lake Michigan | unknown |
| 1692860 | IL | Cook | Winnetka, Lloyd Park Beach | 1970 | 04190000 | Lake Michigan | unknown |
| 1692885 | IL | Cook | Wilmette Harbor | 1975 | 04190000 | Lake Michigan | unknown |
| 1877936 | IL | Lake | Lake Michigan, off the coast of Waukegan, IL | 2008 | 04190000 | Lake Michigan | established |
| 1877937 | IL | Lake | Lake Michigan, off the coast of Waukegan, IL | 2009 | 04190000 | Lake Michigan | established |
| 1877949 | IL | Cook | Southwest Lake Michigan | 2016 | 04190000 | Lake Michigan | established |
| 1878159 | IL | Lake | Highland Park, Lake Michigan | 2010 | 04190000 | Lake Michigan | established |
| 1878162 | IL | Lake | Dead River, Lake Michigan | 2010 | 04190000 | Lake Michigan | established |
Citation for this information:
U.S. Geological Survey, 2026,
Osmerus mordax: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov, Access Date: 6/4/2026