THE MORPHOLOGY OF THE VENOUS SYSTEM IN THE HEAD AND NECK OF THE BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) AND FLORIDA MANATEE (TRICHECHUS MANATUS LATIROSTRIS) By ALEXANDER M. COSTIDIS A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2012 1 © 2012 Alexander M. Costidis 2 To Sentiel “Butch” Rommel who contributed his intellect, time, and friendship and showed me the joys of anatomy. To the anatomists of the world who have experienced the wonder of these animals and have worked painstakingly to understand them. 3 ACKNOWLEDGMENTS I thank my loving family for their support and encouragement, and for giving me a solid foundation upon which stand. Without them I would be lost. I am blessed for having Jennifer’s love, which got me through many difficult times. Butch Rommel’s unwavering enthusiasm about life is one of my most prized possessions and provided me with much of my drive. Brian Stacy’s tireless pursuit of answers and grounded perspective regarding solutions has been supremely instructive and refreshing. Butch’s, Brian’s and Micah Brodsky’s friendship has been priceless. Nicole Stacy’s warm thoughts and warmer smiles have been uplifting. Ann Pabst and Bill McLellan have been invaluable friends and colleagues whose depth, breadth, and commitment are unparalleled. Roger Reep’s gentle guidance and unwavering support made much of this possible and encouraged me through this process. I thank him for his calming presence, his rational intellect and fervent imagination. I thank my supervisory committee for investing their time and energy in helping me see this through. I thank Erick Roden for his jovial demeanor and refreshing jest for life. I am grateful to the numerous stranding organizations around the country for their hard work against often seemingly insurmountable obstacles, and for their provision of such wonderful, sought after specimens. I am especially grateful to the biologists and staff of the Florida Fish and Wildlife Conservation Commission, the University of North Carolina Wilmington stranding network, the Virginia Aquarium stranding team, the Marine Mammal Conservancy, and Lowry Park Zoo for facilitating acquisition of many of my specimens. I am grateful to Dr. David Reese, Mary Wilson, Christine Fitzgerald and the rest of the radiology team at the University of Florida’s College of Veterinary Medicine for their assistance with scanning of specimens at all hours of the day and 4 night. I am grateful to the University of Florida’s College of Veterinary Medicine, Aquatic Animal Health Program and to Ruth Francis-Floyd for their support of my degree and their belief in me. Part of this research was funded by the University of Florida’s College of Veterinary Medicine spring competition grant. 5 TABLE OF CONTENTS page ACKNOWLEDGMENTS .................................................................................................. 4 LIST OF TABLES .......................................................................................................... 10 LIST OF FIGURES ........................................................................................................ 11 LIST OF OBJECTS ....................................................................................................... 17 ABSTRACT ................................................................................................................... 18 CHAPTER 1 INTRODUCTION: COMPARATIVE ANATOMY OF THE HEAD AND NECK VASCULATURE IN DOMESTIC AND MARINE MAMMALS .................................. 20 Significance of Vasculature ..................................................................................... 20 Notable Marine Mammal Adaptations ..................................................................... 22 Terrestrial Mammalian Venous Morphology ........................................................... 25 Extrinsic Arterial Brain Supply in Domestic Mammals ...................................... 27 Extrinsic Arterial Brain Supply in Marine Mammals .......................................... 30 Sealions ..................................................................................................... 31 Seals .......................................................................................................... 32 Sirenians .................................................................................................... 32 Cetaceans .................................................................................................. 33 Arterial Synopsis .............................................................................................. 36 Extrinsic Venous Brain Drainage in Domestic Mammals .................................. 38 Extrinsic Venous Brain Drainage in Marine Mammals ...................................... 39 2 THE GROSS MORPHOLOGY OF THE VENOUS SYSTEM IN THE HEAD AND NECK OF THE BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) ............... 48 Chapter Foreword ................................................................................................... 48 Materials and Methods ............................................................................................ 49 Results .................................................................................................................... 51 Neck ................................................................................................................. 51 Internal jugular veins .................................................................................. 54 External jugular veins ................................................................................. 56 Head ................................................................................................................. 57 Lingual and facial veins .............................................................................. 59 Branches of the facial vein investing the orbit and dorsal maxillary regions .................................................................................................... 63 CNS Veins ........................................................................................................ 64 Discussion .............................................................................................................. 67 6 Comparative Venous Anatomy ......................................................................... 67 Ontogenetic vs. Individual Variability ................................................................ 68 Functional Implications of CNS Vasculature ..................................................... 69 3 DETAILS ON THE VASCULARIZATION OF THE AIR SINUSES AND FAT BODIES IN THE HEAD OF THE BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) ........................................................................................................ 91 Chapter Foreword ................................................................................................... 91 Materials and Methods ............................................................................................ 96 Results .................................................................................................................... 99 Air Sinus and Fat Body Morphology ................................................................. 99 Sinuses ...................................................................................................... 99 Air sinus extent .......................................................................................... 99 Bony walls ................................................................................................ 101 Bony recesses ......................................................................................... 101 Eustachian tube ....................................................................................... 102 Blood-filled part (of the accessory sinus system) ..................................... 103 Fat bodies ................................................................................................ 103 Vascular Anatomy .......................................................................................... 105 Facial vein ................................................................................................ 106 Internal jugular vein (#1, Figures 3-7, 3-9 to 3-10, and 3-13 to 3-14) ....... 107 External jugular vein (#2, Figures 3-9, 3-10, 3-14, 3-15) .......................... 108 Discussion ............................................................................................................ 109 Significance of the Anatomy ........................................................................... 109 Accessory sinus system ........................................................................... 110 Fat bodies ................................................................................................ 114 Clarifications/Inconsistencies ......................................................................... 118 Synopsis ......................................................................................................... 124 4 THE GROSS MORPHOLOGY OF THE VENOUS SYSTEM IN THE HEAD AND NECK OF THE FLORIDA MANATEE (TRICHECHUS MANATUS LATIROSTRIS) ..................................................................................................... 146 Chapter Foreword ................................................................................................