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 mammals Stellar 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 echolocation • Baleens- have 2 blowholes • Baleen 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
Toothed Whales Toothed whales- dolphins, porpoises, sperm whales, killer whale (Orca)
Odontocetes ( toothed whales) • Bear teeth typically numerous peg like teeth, sometimes modified like the single tusk of the Narwhal.
Male Narwhals have two teeth, the left one becomes the tusk that protrudes through the upper jaw.
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
Whales are long-lived, slow reproducing- which is why whaling is threatening their populations.
Breach Right Whale
Breach Orca Humpback
Whale Behavior carrying companion injured member of pod spying