Marine Mammals: Class Mammalia

Order Sirenia: Manatees and Dugongs 1 species of dugong1 species of dugong 3 species of manatees3 species of manatees

Florida Manatee EndangeredEndangered HerbivoreHerbivore Migrate in WinterMigrate in Winter Inhabit tropical watersInhabit tropical waters

Order Carnivora Well-developed claws.Well-developed claws. Strong facial musculatureStrong facial musculature Specialized teeth: canines and incisors.Specialized teeth: canines and incisors.

Suborder Pinnipedia: Sea Lions, Seals and the Walrus

Family Otariidae: Sea Lions

Family Phocidae: Seals

Comparison of Sea lions and Seals Sea Lions (Otariids) External earsExternal ears Long neckLong neck Performs in showsPerforms in shows Use front flippers to swimUse front flippers to swim Can pull hind flipper under body to walk on landCan pull hind flipper under body to walk on land Claws ¾ to end of flipperClaws ¾ to end of flipper Seals (Phocids) No external earsNo external ears Short neckShort neck Do not performDo not perform Use back flippers to swimUse back flippers to swim Can’t rotate hind flippersCan’t rotate hind flippers Claws at end of flippersClaws at end of flippers

Family Odobenidae: Walrus Both males and females have tusks.Both males and females have tusks. Use vibrissae (whiskers) to feed.Use vibrissae (whiskers) to feed.

Family Mustelidae: Sea Otter Two North American Subspecies 1.The Alaska / Northern 2.The California / Southern

Sea Otter Fur Over 1 million hairs/in 2 (Humans have 20,000 hairs on their entire head!)Over 1 million hairs/in 2 (Humans have 20,000 hairs on their entire head!) Need thick fur because they have NO blubberNeed thick fur because they have NO blubber Oil on hair repels waterOil on hair repels water

Oil Spills Oil covers fur and otters die of exposureOil covers fur and otters die of exposure When otters attempt to clean their fur, they ingest the oil and die.When otters attempt to clean their fur, they ingest the oil and die.

Diet Eat invertebrates (urchins,abalone, crabs).Eat invertebrates (urchins,abalone, crabs). Use tools.Use tools.

Polar Bears

Family Ursidae Partially aquatic bears.Partially aquatic bears. Inhabit arctic sea ice, water islands & coastlines.Inhabit arctic sea ice, water islands & coastlines.

Adaptations to the Arctic Small ears which help conserve body heat.Small ears which help conserve body heat. Hind limbs are longer than forelimbsHind limbs are longer than forelimbs 12’’ paws – act like snowshoes12’’ paws – act like snowshoes Non-retractable claw (to grip ice)Non-retractable claw (to grip ice) Thick fur that is oily and water repellentThick fur that is oily and water repellent Skin is black which enables the bear to absorb sunlight energy to warm its body.Skin is black which enables the bear to absorb sunlight energy to warm its body. Have 4 inches of blubberHave 4 inches of blubber

Need 4.4 lbs of fat a day to survive.Need 4.4 lbs of fat a day to survive. Polar bears can smell a seal more than 20 miles away.Polar bears can smell a seal more than 20 miles away. Feed mainly seals, but will scavenge other mammalsFeed mainly seals, but will scavenge other mammals

No natural predators as adultsNo natural predators as adults Threatened species protected under MMPA (Marine Mammal Protection Act)Threatened species protected under MMPA (Marine Mammal Protection Act) No hunting in U.S., but are hunted in Canada.No hunting in U.S., but are hunted in Canada.

Whales Order: Cetacea Suborders: 1. Mysticeti = Baleen whales 2.Odontoceti =Toothed whales

Whale Anatomy Female whales have a genital slit and 2 mammary slits.Female whales have a genital slit and 2 mammary slits. Males have 1 genital slit.Males have 1 genital slit.

Order Mysticeti (Baleen Whales) Largest: BlueLargest: Blue 2 nd largest: Fin2 nd largest: Fin Humpback (sings)Humpback (sings) rg/songs/hmpback3.wavhttp:// rg/songs/hmpback3.wavhttp:// rg/songs/hmpback3.wavhttp:// rg/songs/hmpback3.wav 2 Blowholes2 Blowholes Humpback Minke Whale

Baleen Used for filter feeding Grow down from upper jaw.

Rorqual Many throat groovesMany throat grooves Shorter baleen platesShorter baleen plates Expand capacity of mouthExpand capacity of mouth

Diving Adaptations Have 2x the RBC’s, and 9x the myoglobin (than humans)Have 2x the RBC’s, and 9x the myoglobin (than humans) Countercurrent heat exchange systemCountercurrent heat exchange system Veins surround arteries; heat from blood in arteries is transferred to venous blood.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.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 & BelugaExamples: Sperm, Orca, Dolphins, Porpoises, Narwhal & Beluga Found in fresh and salt waterFound in fresh and salt water Many toothed whales are countershaded or have disruptive coloration (killer whale)Many toothed whales are countershaded or have disruptive coloration (killer whale)

Sperm Whales have teeth in the lower jaw only!Sperm Whales have teeth in the lower jaw only! One BlowholeOne Blowhole No sense of smell in toothed whalesNo sense of smell in toothed whales

Largest member of Dolphin family is OrcaLargest member of Dolphin family is Orca Largest toothed whale is the Sperm WhaleLargest toothed whale is the Sperm Whale Fastest is Dall’s Porpoise: 34 m.p.h.Fastest is Dall’s Porpoise: 34 m.p.h. Sperm Whale Dall’s Porpoise Orca

Cooperative Hunting Orcas, false killer whales, pilot whales,Orcas, false killer whales, pilot whales, & bottlenose dolphins Hunt in packs like wolvesHunt in packs like wolves Humpbacks use bubble netting to surround their preyHumpbacks use bubble netting to surround their prey

Echolocation Enables toothed whales to locate and discriminate objects by listening for echoesEnables toothed whales to locate and discriminate objects by listening for echoes Uses organ called a melon which contains fatsUses organ called a melon which contains fats Acts as an acoustical lens to focus sound waves out to H 2 OActs as an acoustical lens to focus sound waves out to H 2 O Sound travels 4x faster in H 2 O than in air.Sound travels 4x faster in H 2 O than in air. Lower jaw bones = sound receptionLower jaw bones = sound reception