order - sirenia (sirenians) manatees, dugong, sea cows, and mermaids - front flippers/ no rear swim...
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Order - Sirenia (Sirenians)
Manatees, dugong, sea cows, and mermaids - • Front flippers/ no rear• Swim with up and
down tail motion
• Wrinkled skin with little hair
• Padded with blubber• Only strict vegetarian
of marine mammalsStellar Sea Cow- (10 tons)
were extinct 1768- reproduce slowly- 1 calf every 3 years
The Cetaceans (whales, dolphins, and porpoises):
• Of all marine mammals- Whales made the most complete transition to aquatic life (entire life in water)
• They include the largest animal that has ever lived, the blue whale,
• Not fish like- breathe air, endotherms have hair and produce milk
• Elongated skull allows nostrils on top-Blowhole
• Rear flippers- present in embryo stage, but not in adult stage. Hind limbs and pelvis are extremely small do not normally extend out of the body wall.
Cetaceans are divided into 2 groups:Toothless- baleen whales - Mysticeti
Ex. Humpback and Blue whales
Toothed- Carnivorous whales - Odontoceti
Ex. Orca, Sperm Whales, Dolphins, and Porpoises
Baleen Whales• Baleen whales, instead of teeth have rows of
flexible, fibrous plates that hang from the upper jaw. Made of material like hair and nails. The whale feeds by taking big gulp of H2O and squeezing out through baleen, licks food off inside.
Some like humpbacks, are known for complex songs but do not use singing for echolocationBaleens- have 2 blowholesBaleen whales are the largest animal on earth
Rorquals
Rorquals- Baleen whales with ventral pleats like the Blue, Fin, Minke, Sei and Humpback Whales
Minke Whale
Odontocetes ( toothed whales)
• Bear teeth typically numerous peg like teeth, sometimes modified like the single tusk of the Narwhal.
Odontocetes ( toothed whales)
• Sperm whales- accumulate undigested squid beaks and debris called ambergris (used in fine perfume)
• Dolphins- have distinctive beak or snout and travel in pods