Marine Mammal Notes

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Marine Mammal Notes
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Mammal Characteristics

• Endotherms warm blooded. Body temperature
  regulated internally.
• Hair to retain body heat
• Viviparous live bearing animals. Embryos
  develop within the mothers body.
• Placenta membrane that connects baby to mother.
• Mammary glands feed young
• with milk
• Lungs
• 4 Chambered heart

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Pinniped Characteristics

• Examples Seals, sea-lions and walruses
• Pinni winged
• Ped footed
• Thought to have evolved from cats, dogs and
  bears.
• Most live in cold regions
• Predators that feed mostly on fish and squid
• Paddle shaped flippers for swimming but they need
  to rest and breed on land.

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Pinniped Characteristics, contd

• Animals are big less surface area to volume.
• Males are bulls, females are cows, babies are
  pups
• Blubber a thick layer of fat under their skin
• used as a food reserve
• provides buoyancy
• warmth

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Sea lions 5 species

• Characteristics
• Dog-like faces and they bark
• Use front (anterior) flippers to swim
• Rear flippers can be rotated forward so they can
  walk on land.
• Graceful, agile swimmers
• Related to fur seals
• California Sea Lions do tricks at Sea World
  smart

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Seals19 species

• Characteristics
• Cat-like faces
• Rear flippers (posterior) cannot be moved forward
  so they have a hard time moving on land
• Better swimmers than sea lions they can dive
  deeper for a longer period of time.
• Examples Harbor seals and Elephant seals
• Elephant seal males can get up to 20 feet and
  weight 4 tons.

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Comparing Seals and Sea lions

• Seals
• cannot rotate rear flippers
• Short neck
• Swim with rear flippers
• Sea lions
• Can rotate rear flippers
• Long neck
• Swim with front flippers

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Walrus

• Characteristics
• Tusks are used for defense and to pull
  themselves up on the ice. If one breaks with
  more than half remaining, they can regrow.
• Tusks are canine teeth.
• They live in the Arctic.
• Their blubber can weigh up to 900 lbs.
• They have inflatable air pouches in their throat
• They eat shrimp, snails crabs, clams and mussels
• To swim they use their front and rear flippers.

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• Whiskers Act as feelers to suck up bottom
  invertebrates and clams. Full grown species have
  approx. 300 stubby whiskers.