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Common characteristics
Marine mammals share the following characteristics:Give birth to live youngNurse their youngEndothermic – “warm blooded”Have hair
Marine Mammals Groups:
Cetaceans (whales, dolphins, porpoises)Pinnipeds (seals, sea lions, walruses)Sirenians (manatees, dugongs)Polar BearsSea Otters
What’s the difference between a dolphin and a porpoise?
http://vimeo.com/75615317
The main difference between dolphins and porpoises is their teeth! Dolphins have cone-shaped teeth, while porpoises have flattened, spade-shaped teeth.
While not a perfect rule, porpoises generally have a triangular dorsal fin while dolphins have a more curved dorsal fin.
What’s the difference between seals and sea lions?
Sea lions (left) are brown, bark loudly, "walk" on land using their large flippers and have visible ear flaps. Seals have small flippers, wriggle on their bellies on land, and lack visible ear flaps.
Cetaceans Sleek, bullet shaped bodies Strong tail for propulsion Long “mouth” area called a rostrum Move their tails, or flukes up and down
Cetaceans
Must breathe voluntarily (unlike humans)
Breathe through special hole on top of their heads called a blowhole
Deep divers remain near surface for several minutes to “catch their breath”
Cloud-like blow is a mixture of CO2 and unused O2, liquid water spray, and mucus
Cetaceans
Unlike most mammals, cetaceans do not have much hair
Instead, layers of fat under skin called blubber
Keeps animals warm and regulate body temperature
Toothed Whale Characteristics
Eat fish or squid
Use teeth to rip apart prey
Use sound to echolocate, navigate, communicate
Baleen Whales
Baleen allows them to strain their food from the water
Diet includes small prey such as krill, small fish and squid
Behavior of Cetaceans
Vary widely between species Spinner dolphins swim in large pods Blue whales typically alone or in pairs Harbor porpoises prefer shallow waters Sperm whales prefer deep dives to chase
squid Communicate using clicks, whistles, and
groans
Why we Should Care About Whale Poo…..
TED talk
Pinnipeds
All pinnipeds are protected under the Marine Mammal Protection Act (MMPA); some may be designated as "depleted" under the MMPA. Endangered and threatened pinnipeds are further protected under the Endangered Species Act (ESA).
Pinnipeds
Unique because they give birth and nurse on land
Wide range of environments Leopard seal in icy Antarctic Ribbon Seals in Arctic Harbor Seal along temperate
shorelines Hawaiian Monk Seals near Coral
Reef
3 main groups
1) Otaridae (Eared seals)• Includes seals with fur and sea lions
• Have an earflap on outside of their bodies
• Use longer flippers to walk on land by twisting back limbs forward
• Ex: California Sea Lions, Steller Sea Lions, Northern Fur Seals
2) Phocidae (True Seals) Move on land by wriggling on their bellies vertical undulating motion called "galluphing” Ex: Hawaiian Monk Seals, Harbor Seals, and
Ringed Seals
Hawaiian Monk Seal
Harbor Seals
3) Odobenidae (Walruses)
Distinguished by long tusks Use tusks to dig up shellfish from seafloor Also to break through ice and haul themselves
onto ice Unlike other pinnipeds, have very little hair Very thick skin Coarse, sensitive bristles around mouths
replaced yearly
Pinnipeds
Many relax or “haul out” on land in large groups called colonies
Occurs when mothers give birth Occurs when animals lose their fur, or molt Some species like Northern Elephant Seal lose
their entire top layer of skin and hair
Pinnipeds
Haul out areas are not always peaceful Engage in violent fights over mates Northern Elephant Seal males establish
dominance through intense fighting Wins them the right to mate with females Walruses behave similarly
Baby Elephant Seal