W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 2020 The Impacts Of Acute Hypoxic Exposure And Other Concomitant Stressors On The Cardiorespiratory Physiology Of Coastal Elasmobranch Fishes Gail Danielle Schwieterman William & Mary - Virginia Institute of Marine Science, [email protected] Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Physiology Commons Recommended Citation Schwieterman, Gail Danielle, "The Impacts Of Acute Hypoxic Exposure And Other Concomitant Stressors On The Cardiorespiratory Physiology Of Coastal Elasmobranch Fishes" (2020). Dissertations, Theses, and Masters Projects. Paper 1593091930. http://dx.doi.org/10.25773/v5-6hq9-zy38 This Dissertation is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. The impacts of acute hypoxic exposure and other concomitant stressors on the cardiorespiratory physiology of coastal elasmobranch fishes A Dissertation Presented to The Faculty of the School of Marine Science The College of William & Mary In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Gail Danielle Schwieterman May 2020 APPROVAL PAGE This dissertation is submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Gail Danielle Schwieterman Approved by the Committee, April 2020 Richard W. Brill, Ph.D. Committee Chair / Advisor Mary C. Fabrizio, Ph.D. Kevin C. Weng, Ph.D. Emily B. Rivest, Ph.D. Holly A. Shiels, Ph.D. University of Manchester Manchester, UK This Ph.D. is dedicated to the makers of escitalopram, without which I never would have completed this document, and to the friends and family who encouraged me to get the medical help I needed iii TABLE OF CONTENTS ACKNOWLEDGEMENTS ........................................................................................... ix LIST OF TABLES ......................................................................................................... x LIST OF FIGURES ....................................................................................................... xi AUTHOR’S NOTE ........................................................................................................ xiv ABSTRACT ................................................................................................................... xv CHAPTER I — Introduction: Elasmobranch cardiorespiratory physiology and responses to stress ................................................................................................... 2 Elasmobranch Fishes ......................................................................................... 3 Anthropogenic Stress ......................................................................................... 5 Climate Change ...................................................................................... 5 Fishing Pressure ..................................................................................... 7 Cardiorespiratory Physiology of Fishes ............................................................. 10 The Elasmobranch Cardiorespiratory System ................................................... 14 The Cardiorespiratory Stress Response of Fishes .............................................. 17 Dissertation Aims and Structure ........................................................................ 18 References .......................................................................................................... 22 Figures................................................................................................................ 35 CHAPTER II — Combined effects of acute temperature change and elevated pCO2 on the metabolic rates and hypoxia tolerances of clearnose skate (Rostaraja elganteria), summer flounder (Paralichthys dentatus), and thorny skate (Amblyraja radiata) ............................................................................ 38 Abstract .............................................................................................................. 39 Introduction ........................................................................................................ 40 iv Materials and Methods ....................................................................................... 44 Results ................................................................................................................ 49 Standard Metabolic Rate and Q10 .......................................................... 49 Maximum Metabolic Rate and Aerobic Scope ...................................... 50 Hypoxia Tolerance ................................................................................. 50 Discussion .......................................................................................................... 51 Conclusions ........................................................................................................ 60 Acknowledgements ............................................................................................ 61 References .......................................................................................................... 62 Tables ................................................................................................................. 73 Figures................................................................................................................ 75 Supplementary Material ..................................................................................... 80 CHAPTER III — Drivers of hypoxia tolerance in elasmobranch fishes: comparing blood oxygen affinity between clearnose skate and summer flounder .......................................................................................................................... 81 Abstract .............................................................................................................. 82 Introduction ........................................................................................................ 83 Materials and Methods ....................................................................................... 90 Animal Collection and Maintenance ..................................................... 90 Tonometry and Hematology .................................................................. 91 Data Processing and Statistical Analysis ............................................... 93 Results ................................................................................................................ 95 Discussion .......................................................................................................... 96 Conclusions ........................................................................................................ 104 v Acknowledgements ............................................................................................ 105 References .......................................................................................................... 106 Tables ................................................................................................................. 116 Figures................................................................................................................ 117 Supplementary Material ..................................................................................... 128 CHAPTER IV — A search for red blood cell swelling in five elasmobranch fishes ....................................................................................................... 134 Abstract .............................................................................................................. 135 Introduction ........................................................................................................ 136 Materials and Methods ....................................................................................... 140 Results ................................................................................................................ 143 Discussion .......................................................................................................... 145 Possible Functions of RBC Swelling ..................................................... 149 Possible Mechanisms of Swelling in Elasmobranch Fishes .................. 152 Preservation of CO2 Excretion ............................................................... 153 Future Work ........................................................................................... 155 Conclusions ........................................................................................................ 155 Acknowledgements ............................................................................................ 156 References .......................................................................................................... 157 Figures................................................................................................................ 165 CHAPTER V — The effects of elevated potassium, acidosis, reduced oxygen levels, and temperature on the functional properties of isolated myocardium from three elasmobranch fishes: clearnose skate (Rostraja eglanteria), smooth dogfish (Mustelus canis), and