BIO 358 1st Edition Lecture 3 Outline of Last Lecture II Characteristics of Pinnipeds III Pinniped Breeding IV Human impacts on pinnipeds A indirect B direct V Pinniped Distribution VI 3 families of pinnipeds A Family Otariidae i Characteristics ii Example species B Family Phocidae i Characteristics ii Example species C Family Odobenidae i Example specie D Fun words about scrotums Outline of Current Lecture VII Odobenidae Walrus VIII Mustelidae Otters A Sea Otter B Marine Otter IX Ursidae Polar Bear X Order Sirena A Manatee B Dugong C Steller s Sea Cow XI Beginning of Cetaceans Current Lecture Walrus odobenus rosmarus largest pinniped except for the elephant seal These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute tooth walker only extant species in order and family odobenidae only extant species with tusks both males and females have tusks for fighting and for pulling out onto ice and for hanging on to ice swim like phocids using their hind flippers for lift based thrust force and they have one side expanded and one side folded in lift based thrust Otters Mustelids sea otter and marine otter both are endangered exploited in 1740 s for fur 5 million sea otters killed in 150 years until 1911 1911 north pacific fur seal convention protected fur seals AND otters sea otter s rose after this Sea otter Enhydra lutris largest otter never seen on land lies on its back and holds air in its large lungs and fur which makes it VERY BUOYANT can hold rocks and abalones on its chest and still float use hind flippers to produce lift based thrust forces for high speed swimming link hind limbs and dorsal ventrally oscillate Marine Otter Lontra feline more terrestrial than a sea otter most recent anscestor bear sea cat found off the coast argentina and chile more terrestrial than the sea otter poached for fur coats less than 1 000 individuals alive Family Ursidae Polar Bear Ursus martimus only marine ursid most recently evolved bear 5 1 1 million years old not a long time closely related to brown bears more streamlined than other bears uses drag based thrust o i e Putting an oar in a water thrust is not generated during the entire stroke o Least efficient swimming style not as adapted for marine life as other marine mammals Eats large endotherms seals Directly exploited for fur Listed as threatened may 2008 Dr Ian sterling studies these guys he noticed a decrease in body condition and reproductive output over time they will most likely be endangered soon because of GLOBAL CLIMAT CHANGE THESE ANIMALS ARE DEPENDANT ON ICE o They are not highly adapted to swimming long distances because of their morphology Order Sirena manatees and dugongs Restricted to warm waters 15 celcius 60 farenhite colder than this system wide breakdown called cold stress death Almost exclusively herbivores sometimes they eat animals living on grass hind gut digesters non ruminant herbivore eat A LOT every day 55 90kg have special teeth that are replaced through horizontal replacement teeth emerge and reach the front and then fall out like a conveyor belt slow moving and placid animals meat keeps well people like to eat them low metabolism 70 Of time spent on sea floor most closely related to elephants hyraxes Trichiridae family manatees o Teat in axilla arm pit o Many killed by boat strikes o Boat strike scar patterns identification o Some have become dependant on warm water outfalls of power plants conservation issue o COLD SHOCK happens very easily manatees found in NC from may to October if they are found in September they are dead from the cold o Have hugeeee tail flukes o West Indian Manatee Trichechus Manatus Endangered Sensitive to cold stress and need warm water Family dugong dugongs o Dugong Dugong dugon Endangered Found in the indo pacific Better swimmer cetacean like fluke More streamline Lift base thrust for entire locomotary cycle Steler s sea cow Hyrodamalis gigas o HUGE ANIMAL o Found in the arctic o No functional teeth o Feed on kelp o Discovered in 1741 and was hunted for food o Extinct by 1768 27 years between discovery and extinction o Keratin teeth plates crushing kelp Cetaceans Telescope skull Nasal bone on top of head blow hole narins Extended premaxilla and maxilla Baleen Right whales are skim feeders Premaxilla and maxilla with paleen plates Caratinized 350 plates per side Hiar like fringes at ends of plates They gulp in water close their mouths and then push it backwards through the baleen