Marine Mammals

Order Sirenia: Manatees and Dugongs 1 species dugong 3 species manatees

Florida Manatee Endangered Herbivore Migrate in Winter Inhabit tropical waters

Order Pinnipedia: Sea Lions, Seals and the Walrus

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 Phocidae: Seals

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