Marine Mammal NotesMarine Mammal Notes

Mammal CharacteristicsMammal Characteristics Endotherms – warm blooded. Body Endotherms – warm blooded. Body

temperature regulated internally.temperature regulated internally. Hair – to retain body heatHair – to retain body heat Viviparous – live bearing animals. Viviparous – live bearing animals.

Embryos develop within the mother’s Embryos develop within the mother’s body.body.

Placenta – membrane that connects baby Placenta – membrane that connects baby to mother.to mother.

Mammary glands – feed young Mammary glands – feed young with milkwith milk LungsLungs 4 Chambered heart4 Chambered heart

Pinniped CharacteristicsPinniped Characteristics

Examples: Seals, sea-lions and walrusesExamples: Seals, sea-lions and walruses Pinni – “winged”Pinni – “winged” Ped – “footed”Ped – “footed” Thought to have evolved from cats, dogs and Thought to have evolved from cats, dogs and

bears.bears. Most live in cold regionsMost live in cold regions Predators that feed mostly on fish and squidPredators that feed mostly on fish and squid Paddle shaped flippers for swimming but they Paddle shaped flippers for swimming but they

need to rest and breed on land.need to rest and breed on land.

Pinniped Characteristics, cont’dPinniped Characteristics, cont’d

Animals are big – less surface area to Animals are big – less surface area to volume.volume.

Males are bulls, females are cows, babies Males are bulls, females are cows, babies are pupsare pups

Blubber – a thick layer of fat under their Blubber – a thick layer of fat under their skinskin

*used as a food reserve*used as a food reserve*provides buoyancy*provides buoyancy*warmth *warmth

Sea lionsSea lions 5 species5 species

CharacteristicsCharacteristics

Dog-like faces and they “bark”Dog-like faces and they “bark” Use front (anterior) flippers to swim Use front (anterior) flippers to swim Rear flippers can be rotated forward so they can Rear flippers can be rotated forward so they can

walk on land.walk on land. Graceful, agile swimmersGraceful, agile swimmers Related to fur sealsRelated to fur seals California Sea Lions – do tricks at Sea World – California Sea Lions – do tricks at Sea World –

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SealsSeals19 species19 species

CharacteristicsCharacteristics Cat-like facesCat-like faces Rear flippers (posterior) Rear flippers (posterior)

cannot be moved forward so cannot be moved forward so they have a hard time they have a hard time moving on landmoving on land

Better swimmers than sea Better swimmers than sea lions – they can dive deeper lions – they can dive deeper for a longer period of time.for a longer period of time.

Examples: Harbor seals Examples: Harbor seals and Elephant sealsand Elephant seals

Elephant seal males can get Elephant seal males can get up to 20 feet and weight 4 up to 20 feet and weight 4 tons.tons.

Comparing Seals and Sea lionsComparing Seals and Sea lions

SealsSeals cannot rotate rear cannot rotate rear

flippersflippers Short neckShort neck Swim with rear flippersSwim with rear flippers

Sea lionsSea lions Can rotate rear flippersCan rotate rear flippers Long neckLong neck Swim with front flippersSwim with front flippers

WalrusWalrus CharacteristicsCharacteristics

Tusks are used for defense and to pull Tusks are used for defense and to pull themselves up on the ice. If one breaks with themselves up on the ice. If one breaks with more than half remaining, they can regrow.more than half remaining, they can regrow.

Tusks are canine teeth. Tusks are canine teeth. They live in the Arctic.They live in the Arctic. Their blubber can weigh up to 900 lbs. Their blubber can weigh up to 900 lbs. They have inflatable air pouches in their throatThey have inflatable air pouches in their throat They eat shrimp, snails crabs, clams and They eat shrimp, snails crabs, clams and

musselsmussels To swim they use their front and rear flippers. To swim they use their front and rear flippers.

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