Marine Mammal Notes Mammal Characteristics Endotherms warm blooded
Marine Mammal Notes
Mammal Characteristics Ø Endotherms – warm blooded. Body temperature regulated internally. Ø Hair – to retain body heat Ø Viviparous – live bearing animals. Embryos develop within the mother’s body. Ø Placenta – membrane that connects baby to mother. Ø Mammary glands – feed young with milk Ø Lungs Ø 4 Chambered heart
Pinniped Characteristics Examples: Seals, sea-lions and walruses Ø Pinni – “winged” Ø Ped – “footed” Ø Thought to have evolved from cats, dogs and bears. Ø Most live in cold regions Ø Predators that feed mostly on fish and squid Ø Paddle shaped flippers for swimming but they need to rest and breed on land. Ø
Pinniped Characteristics, cont’d Ø Animals are big – less surface area to volume. Ø Males are bulls, females are cows, babies are pups Ø Blubber – a thick layer of fat under their skin *used as a food reserve *provides buoyancy *warmth
Sea lions 5 species Ø 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. Ø Graceful, agile swimmers Ø Related to fur seals Ø California Sea Lions – do tricks at Sea World – smart Ø Ø Ø
Seals 19 species Characteristics Cat-like faces Rear flippers (posterior) cannot be moved forward so they have a hard time moving on land Ø Better swimmers than sea lions – they can dive deeper for a longer period of time. Ø Examples: Harbor seals and Elephant seals Ø Elephant seal males can get up to 20 feet and weight 4 tons. Ø Ø Ø
Comparing Seals and Sea lions Seals cannot rotate rear flippers Ø Short neck Ø Swim with rear flippers Ø Sea lions Can rotate rear flippers Ø Long neck Ø Swim with front flippers Ø
Walrus Ø 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. Ø Tusks are canine teeth. Ø They live in the Arctic. Ø Their blubber can weigh up to 900 lbs. Ø They have inflatable air pouches in their throat Ø They eat shrimp, snails crabs, clams and mussels Ø To swim they use their front and rear flippers. Ø
Ø Whiskers: Act as feelers to suck up bottom invertebrates and clams. Full grown species have approx. 300 stubby whiskers.
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