Transcript Mammals - part 3

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 1768reproduce slowly- 1
calf every 3 years
• Marine mammal act of 1972- protects sale of
marine mammal products
Kingdom- Animalia
Phylum- Chordota
Class- Mammalia
Order- Cetacea
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,
the highly intelligent and communicative
dolphins;
the tusked narwhals and blind river
dolphins
and singing humpback whales-nearly 80
living species in all.
• Body- fish like- (convergent evolution) similar life style
• Not fish like- breathe air, endotherms have hair and
produce milk
• Elongated skull allows nostrils on top-Blowhole
• Forelimbs are specialized to form flippers
• 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.
Fetus of a white sided dolphin
• Dorsal fin in many
•Tail with two finlike flukes
arranged horizontally.
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
Toothed Whales
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 Baleen whales have ventral
pleats to increase size of mouth
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 whalesdolphins, 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 reproducingwhich is why whaling is threatening their
populations.
Whale - spout or blow- exhale through
blowhole.
spout or blow
spout or blow
Breach
Breach
Right Whale
Breach
Humpback
Orca
Whale Behavior
carrying companion
injured member of pod
spying
Beluga