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Flashcards in Ocnquiz12 Deck (25)
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Give the evolutionary History of Marine animals

Marine animals were all once land animals. Many suggest that these animals returned to the ocean due to the abundance of food


List the characteristics shared by all mammals

Warm blooded
they breathe air
they have hair
they bear live young
The females of each species have mammary glands


list the three mammalian (taxonomic) orders



list the three types of animals in order Carnivora.

sea otters, polar bears, and pennipeds


list the three types of pinnipeds

walruses, seals, and sea lions


Where is the sea otter habitat

Kelp beds in the costal water on the eastern north pacific ocean


Explain why sea otters require a high caloric diet?

Because they lack the insulate effects of blubber


Explain why polar bears have hollow hairs

for better insulation


Where is the polar bear habitat

the arctic


to list the two types of animals in order Sirenia.

Manatees and dugongs


Where are the manatee and dugong habitats?

Manatees are concentrated in the costal areas of the tropical atlantic, while dugongs are concentrated in the tropical parts of the indian and western pacific oceans


Give the primary food for sirenians

Shallow water costal grasses


Give two reasons why sirenians are listed as endangered species

Their ecosystem is endangered due to humans, for sirenians live in costal waters where humans commerce, use of recreation, and development, and water disposal, which kills their habitat and food sources


List the characteristics shared by all cetaceans

An elongated skull
blowholes ontop of skulls
very few hairs
a horizontal fin called a fluke that is used for propulsion by vertical movements


Explain how cetaceans' skin evolved to permit increased swimming speeds.

their outer layer skin is 80 percent water, containing spongey narrow canals which decreases pressure at the skin


How have cetaceans evolved to be able to dive to depths deeper than 2800 m?

cetaceans have evolved to have structures that allow them to use oxygen efficiently, muscular adaptations, and the ability to resist nitrogen narcosis


Contrast the oxygen usage per breath for cetaceans and humans

Cetaceans take about 1 to 3 breathes per minute while humans take 15 breathes per minute


Explain how cetaceans' muscles evolved to permit deep dives

their muscle tissue is relatively insensitive to high levels of carbon dioxide. their muscles can continue to function through anaerobic respiration when oxygen becomes depleted


Explain how cetaceans evolved to reduce nitrogen absorption in blood during deep dives.

Cetaceans have collapsable rib cages, so the lungs can collapse to remove all air from the alveoli. this prevents blood from absorbing gases, minimizing nitrogen narcosis


List the two cetacean suborders and give and example of each type.

Odontocetti (dolphins, porpoises, killer whales, and sperm whales) and mysticeti (blue whale, finback whale, and humpback whale, grey whale)


Which cetacean is the most vocal

Odontocetti (the sperm whale)


Describe the morphological differences between porpoises and dolphins.

Both exhibit porpoising
porpoises are smaller and have more stout , triangular fins , and blunt teeth
Dolphins are more elongated and streamlined, have longer rostrums, sickle shaped fins, pointy teeth


Give the uses of echolocation by cetaceans

it's used to determine the distance and location of objects
helps to stun prey


Explain how the increasing number of ships is affection cetaceans

there is growing concern that noise population in the ocean is affecting cetaceans. this noise is unknown to affect behavior and communication


Explain why some scientists think that dolphins are highly intelligent

They can communicate using sounds
Dolphins have been known to save drowning people
Their brains are proportionally bigger than their body
their brains are highly convoluted