Order Sirenia: Manatees and Dugongs • 1 species dugong • 3 species manatees
Florida Manatee • Endangered • Herbivore • Migrate in Winter • Inhabit tropical waters
Family Otariidae: Sea Lions • External ears • Long neck • Performs in shows • Pull hind flipper under body • Claws ¾ to end of flipper
Family Phocidae: Seals • No external ears • Short neck • Back flippers to swim • Can’t rotate hind flippers • Claws at end of flippers
Family Odobenidae: Walrus • Use vibrissae (whiskers) to feed.
Order Carnivora: Sea Otter Two North American Species • The Alaskan • The Californian
Prized for pelt • Over 1 million hairs/in2 • Need thick fur because they have NO blubber • Oil on hair to repel water
Oil Spills • Oil covers fur and otters die of exposure • When otters attempt to clean their fur, they ingest the oil and die.
Diet • Eat invertebrates (urchins and abalone). • Use tools.
Order Carnivora: Polar Bears • Well-developed claws, strong facial musculature, specialized teeth.
Family Ursidae • Partially aquatic bears. • Inhabit arctic sea ice, water islands & coastlines.
Adaptations to the Arctic • Small ears which help conserve body heat. • 12’’ paws – act like snowshoes • Non-retractable claw (to grip ice) • Thick fur • Fur is oily and water repellent • Skin is black which enables the bear to absorb sunlight energy to warm its body. • Have 4 inches of blubber
Need 4.4 lbs of fat a day to survive. • Polar bears can smell a seal more than 20 miles away. • Feed mainly seals, but will scavenge other mammals
No natural predators as adults • Threatened species protected under MMPA (Marine Mammal Protection Act) • No hunting in U.S., but are hunted in Canada.
Whales Order: Cetacea Suborders: 1. Mysticeti = Baleen whales • Odontoceti =Toothed whales
Whale Anatomy • Female whales have a genital slit and 2 mammary slits. • Males have 1 genital slit.
Order Mysticeti (Baleen Whales) • Largest: Blue • 2nd largest: Fin • Humpback (sings) • http://www.oceanmammalinst.org/songs/hmpback3.wav • 2 Blowholes Humpback Minke Whale
Baleen • Used for filter feeding • Grow down from upper jaw.
Rorqual • Many throat grooves • Shorter baleen plates • Expand capacity of mouth
Diving Adaptations • Have 2x the RBC’s, and 9x the myoglobin (than humans) • Countercurrent heat exchange system • Veins surround arteries; heat from blood in arteries is transferred to venous blood. • Mammalian diving reflex- blood is shunted away from extremities to vital organs.
Gray Whale Undertakes the longest migration (11,000 miles)
Order Odontoceti • Examples: Sperm, Orca, Dolphins, Porpoises, Narwhal & Beluga • Found in fresh and salt water • Many toothed whales are countershaded or have disruptive coloration (killer whale)
Sperm Whales have teeth in the lower jaw only! • One Blowhole • No sense of smell in toothed whales
Largest member of Dolphin family is Orca • Largest toothed whale is the Sperm Whale • Fastest is Dall’s Porpoise: 34 m.p.h. Orca Sperm Whale Dall’s Porpoise
Cooperative Hunting • Orcas, false killer whales, pilot whales, & bottlenose dolphins • Hunt in packs like wolves • Humpbacks use bubble netting to surround their prey
Echolocation • Enables toothed whales to locate and discriminate objects by listening for echoes • Uses organ called a melon which contains fats • Acts as an acoustical lens to focus sound waves out to H2O • Sound travels 4x faster in H2O than in air. • Lower jaw bones = sound reception