Degree Name

Master of Science (MS)

Semester of Degree Completion


Thesis Director

William W. Scott


There is a paucity of information concerning the occurrence and distribution of the Saprolegniaceae of Illinois. These fungi, commonly called "water molds", are of particular interest as many are potential parasites of fish, crustaceans, and other aquatic plant and animal life. It is of considerable interest to students of the fungi and of practical value to the fisheries biologists and environmentalists to have available a means of identification for these organisms.

This paper provides a descriptive and photomicrographic account of the Saprolegniaceae of Illinois. Included herein are dichotomous keys to the genera of this family as well as generic descriptions for each of the 12 genera known to occur in Illinois. For each genus containing more than a single species, a dichotomous key is provided for the identification of species. A total of 68 species is reported herein. Each of 50 species is illustrated with four or more separate figures, these designed to emphasize the diagnostic characteristics for each species. Each species is further defined by brief notes concerning the distinguishing species characteristics. The species reported herein include twenty new Illinois state records and one, Achlya radiosa Maurizio, a new North American record.