A. John Gatz

William and Elizabeth Austin Professor of Zoology


  • A.B., Dickinson College
  • Ph.D., Duke University


John Gatz teaches courses in human biology, evolution, vertebrates, and population and community ecology. His most well-known research used the morphology of different species of fishes to infer their ecological interactions and understand their community ecology. He currently is involved in a massive study of several species of fishes (more than 21,000 fishes individually tagged) in a local stream. The data already have shown that electrofishing, a standard fisheries technique currently under some criticism, does not harm these fish.

Gatz serves as Ohio Wesleyan’s Chief Health Professions Advisor; he works primarily with pre-medical and pre-dental students.

Areas of Interest/Expertise

Gatz has diverse research interests and has studied and published on topics ranging from thermobiology of jellyfish and amphibians to sexual selection in frogs and toads to optimal foraging in beavers to community ecology of stream fishes. His current research interests focus on lodge site selection by beavers and seasonal patterns of movement and growth in several species of local stream fishes.


  • Gatz, A. John., et al. “Effects of Repeated Electroshocking on Condition, Growth, and Movement of Selected Warmwater Stream Fishes.” North American Journal of Fisheries Management. 28 (2008): 792–798.
  • Gatz, A.J. Jr. 1979. Community organization in fishes as indicated by morphological features. Ecology 60(4): 711–718.
  • Gatz, A.J. Jr. and A.L. Harig. 1993. Decline in the Index of Biotic Integrity of Delaware Run, Ohio, over 50 years. Ohio Journal of Science 93(4): 95–100.
  • Raffel, T.R. and A.J. Gatz, Jr. 2003. The orientation of beavers (Castor canadensis) when cutting trees. Ohio Journal of Science 103(5): 143–146.

Contact Info


Schimmel/Conrades Science Center 193
Ohio Wesleyan University
Delaware, OH 43015
P P 740-368-3889
E ajgatz@owu.edu