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Marine Mammal Notes. Mammal Characteristics. Endotherms – warm blooded. Body temperature regulated internally. Hair – to retain body heat Viviparous – live bearing animals. Embryos develop within the mother’s body. Placenta – membrane that connects baby to mother.
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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 mother’s body. • Placenta – membrane that connects baby to mother. • Mammary glands – feed young with milk • Lungs • 4 Chambered heart
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.
Pinniped Characteristics, cont’d • 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
Sea lions5 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
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.
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
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.
Whiskers: Act as feelers to suck up bottom invertebrates and clams. Full grown species have approx. 300 stubby whiskers.