INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand corner and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6" x 9" black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. University Microfilms International A Bell & Howell Information Company 300 North Zeeb Road, Ann Arbor, Ml 48106-1346 USA 313/761-4700 800/521-0600 Order Number 9130409 The role of pumpkinseed sunfish in structuring snail assemblages in northern Wisconsin lakes Klosiewski, Steven Paul, Ph.D. The Ohio State University, 1991 UMI 300 N. Zeeb Rd. Ann Arbor, MI 48106 THE ROLE OF PUMPKINSEED SUNFISH IN STRUCTURING SNAIL ASSEMBLAGES IN NORTHERN WISCONSIN LAKES DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University By Steven Paul Klosiewski, B.S., M.S. The Ohio State University 1991 Dissertation Committee: Approved by R. A. Stein J. Bart W. M. Masters Department of Zoology ACKNOWLEDGEMENTS Roy Stein contributed to many aspects of this work from its development to its completion. Jim Klosiewski, Barry Benson, Beth Campbell, and Mark Humpert provided assistance in the field and processed most of the snail samples. Julie Ballinger counted and measured the majority of snails. Jim, Norbert, and John Klosiewski helped build the cages; the Cesarz Drywall Company provided the tools and warehouse space for cage building. Jon Bart and W. Mitch Masters provided constructive criticism on various drafts of this dissertation. This study was funded by U.S. National Science Foundation grant BSR85-00772 to Roy A. Stein. VITA April 25, 1955 ................................. Born - Milwaukee, Wisconsin 1978 ................................................. B.S., University of Wisconsin - Stevens Point, Stevens Point, Wisconsin 1979-1981 ........................................ Graduate Research Assistant, Department of Zoology, The Ohio State University, Columbus, Ohio 1981 ................................................. M.S., Department of Zoology, The Ohio State University, Columbus, Ohio 1981-1983............................................. Research Technician, Savannah River Ecology Laboratory, Aiken, South Carolina 1983-1988 ........................................ Graduate Research and Teaching Assistant, Department of Zoology, The Ohio State University, Columbus, Ohio 1988-Present ................................... Wildlife Biologist, U.S. Fish and Wildlife Service, Marine and Coastal Bird Project, Anchorage, Alaska PUBLICATIONS Carline, R.F., and S.P. Klosiewski. 1985. Responses of fish populations to mitigation structures in two small channelized streams in Ohio. North American Journal of Fisheries Management 5:1-11. Lodge, D.M., K.M. Brown, S.P. Klosiewski, R.A. Stein, A.P. Covich, B.K. Leathers, and C. BrOnmark. 1987. Distribution of freshwater snails: spatial scale and the relative importance of physicochemical and biotic factors. American Malacological Bulletin 5:73-84. Bart, J., and S.P. Klosiewski. 1989. Use of presence-absence to measure changes in avian density. Journal of Wildlife Management 53:847-852. FIELDS OF STUDY Major Fields: Zoology TABLE OF CONTENTS ACKNOWLEDGEMENTS................................................................................ ii V ITA ...................................................................................................................iii LIST OF TABLES......................................................................................... vii LIST OF FIGURES............................................................................. ix INTRODUCTION ......................................................................................... 1 CHAPTER PAGE I. PUMPKINSEED SUNFISH PREFERENCE FOR SNAILS: AN EVALUATION OF CURRENT FORAGING MODELS.................. 5 Introduction.............................................................................. 5 Methods.................................................................................... 8 Results .................................................................................... 14 The act of predation..................................................... 14 Snail shell characteristics .......................................... 14 Single-snecies experiments.......................................... 17 Prev profitabilities....................................................... 23 Multispecies experiments- equal sizes and densities ............................................................ 33 Multispecies experiments - varying sizes and densities ............................................................ 38 Effect of habitat structural complexity ......... 42 Discussion................................................................................ 47 The role of size ............................................................ 47 Relation to models of prev selection........................... 50 Implications for the fie ld............................................. 54 Literature Cited....................................................................... 56 II. EVALUATING AN OPTIMAL FORAGING MODEL INCORPORATING CAPTURE SUCCESS AND SIMULTANEOUS ENCOUNTERS WITH PREY ........................... 60 Introduction.............................................................................. 60 The Pumpkinseed Sunfish-Snail Interaction ............ 62 The M odel..................................................................... 63 Materials and Methods .......................................................... 71 Results .................................................................................... 74 Model Simulations....................................................... 74 Comparison with results from laboratory experiments....................................................... 78 Discussion................................................................................ 82 Summary.................................................................................. 89 Literature Cited....................................................................... 90 III. PISH PREDATION AND ITS ROLE IN STRUCTURING SNAIL ASSEMBLAGES IN NORTHERN WISCONSIN LAKES ............... 92 Introduction.............................................................................. 92 Methods.................................................................................... 96 Results ......................................................................................103 The snails ...................................................................... 103 Response of snail assemblages to predator density manipulations........................................109 High pumpkinseed density la k e...................................109 Low pumpkinseed density lake ...................................115 Discussion................................................................................. 125 Literature Cited.........................................................................130 LIST OF REFERENCES............................................................................... 135 APPENDICES................................................................................................. 144 Appendix A ...........................................................................................144 Appendix B ...........................................................................................147 LIST OF TABLES TABLE PAGE 1. Regressions of crushing resistance versus snail size based on snails collected during 1984-1987. Cr=a+b'L for single prey type experiments and Cr=aLb for multiple prey type experiments. L is snail length (mm). Regressions for Helisnmn ancens and Oannnelnnrm dedsum were based on data from more than one year because of small sample sizes within years.................................... 16 2. Regressions of handling times as a function of fish size and snail crushing resistance for snails that were consumed. Htsa+bi’C-ba’FC, where Ht is handling time (s), F is fish length (mm), and C is crushing resistance (N). Significance levels are in parentheses........................................................................................... 26 3. ANOVA tables for regressions of handling times, of rejected snails, on snail mass, crushing resistance, and fish length. SS= partial sums of squares......................................................................