Degree Name

Master of Science (MS)

Semester of Degree Completion


Thesis Director

L. Stephen Whitley


Species composition, distribution, abundance, and water quality relationships of aquatic oligochaetes occurring in the upper Cache River system, southern Illinois were investigated. Forty-two taxa of oligochaetes including 16 naidids, 22 tubificids and representatives of the families Aeolosomatidae, Branchiobdellidae, Enchytraeidae, and Lumbriculidae were collected. Four species of oligochaetes new to Illinois, Limnodrilus psammophilus Loden, L. rubripenis Loden, Psammoryctides (Spencerius) californianus Brinkhurst, and Haemonais waldvogeli Bretscher were collected during this study. Another species of Limnodrilus new to science is reported here, as yet undescribed. The thesis that aquatic oligochaetes can be used as true water quality indicator organisms is rejected. It is suggested that the relative abundance and species composition of the total invertebrate fauna be used in conjunction with monitored water quality parameters to identify trends in the physical, chemical, and biological communities.