marine science final test

amphibians

animals evolved from fish that were well adapted to life both on land and water. marine reptiles then came from amphibians

4 groups of reptiles alive today

sea turtles, sea snakes, marine lizards, saltwater crocodiles

reptiles have a dry scaly skin to keep water inside, and they are ectotherms so they live in warm environments

amphibians

animals evolved from fish that were well adapted to life both on land and water. marine reptiles then came from amphibians

4 groups of reptiles alive today

sea turtles, sea snakes, marine lizards, saltwater crocodiles

reptiles have a dry scaly skin to keep water inside, and they are ectotherms so they live in warm environments

aquatic reptiles adaptations

lungs, meaning they have to come up for air

amniotic egg, a large yolk to nourish the developing embryo and a case to keep it from drying out

3-chambered heart in every reptile except alligators/crocodiles

marine reptiles need salt glands, so they don’t need freshwater, and excrete concentrated urine by reabsorbing most of the water

marine birds adaptations

down feathers which are small and keep warm, contour feathers that cover the wings/body and are used for flight

some birds also have powder feathers to repel water

special gland near tail with a waterproof oil birds put all over them

some have webbed feet to paddle and swim

hollow bones (flight) or dense bones (for those who dive)

salt glands

chondrichthyes

sharks, skates, and rays, plus holocephalis

we are more related to bony fish than

bony fish (osteichthyans) are to sharks

do sharks have scales?

scales are fed by blood vessels and covered in dentin, “skin teeth”

how do sharks have red blood cells

sharks produce red blood cells in their spleen and epigonal organ, despite not having bones

how did sharks survive all this time?

cartilage is lighter and more flexible so you can bend more and weight less (power + maneuverability)

muscles primarily connect to a stretchy network made of collagen, as shark bends itself the collagen stretches and energy is stored, helping fuel the next bend

bony fishes position

median fins

some have finlets and keels (pelagic fishes)

more evolved fish have…

pelvic fins that are closer to their head

everything else

marine mammal characteristics

warm-blooded, breath air, hair, bear live young, milk, 3 ear bones, 4 chambered hearts, intelligent

how do they survive

thermoregulation, blubber, fur to keep them dry, vasodilation (controlled body temptations)

carnivora class

seals, sea lions, walruses, polar bears, sea otters

pinnepeds (huge flippers)

sirenia

manatees/dugongs

closely related to elephants, herbivores

cetacea

whales, dolphins, porpoises

stream-lined bodies/skin structure to be fast

absorb lots of oxygen so they can dive far down and do not get affected by CO2 build up

collapsible lungs

some have echolocation, some have baleen (kinda like teeth)