![](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/all-about-shark-title/6084556-8-eng-US/all-about-shark-title_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/all-about-shark-title/6084556-8-eng-US/all-about-shark-title_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/all-about-shark-title/6084556-8-eng-US/all-about-shark-title_full_1468.png 1401w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/all-about-shark-title/6084556-8-eng-US/all-about-shark-title_full_1980.png 1401w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/all-about-shark-title/6084556-8-eng-US/all-about-shark-title_full_2475.png 1401w)
![title that reads "All About Sharks" in blue font](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/aas-mobile-title/6147207-3-eng-US/aas-mobile-title_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/aas-mobile-title/6147207-3-eng-US/aas-mobile-title_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/aas-mobile-title/6147207-3-eng-US/aas-mobile-title_full_1468.png 1001w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/aas-mobile-title/6147207-3-eng-US/aas-mobile-title_full_1980.png 1001w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/aas-mobile-title/6147207-3-eng-US/aas-mobile-title_full_2475.png 1001w)
Sharks and their relatives have been swimming in Earth’s oceans for about 450 million years. That's long before there were humans, dinosaurs, or even trees!
Sharks Are Fishes, Not Mammals Like Whales.
Unlike their ancestors the bony fishes, sharks have firm-but-flexible skeletons made of cartilage. So do their close relations the rays, skates, sawfishes , and chimaeras. Cartilage is the same stuff that stiffens your ears and the tip of your nose.
![bull shark swimming](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/intro-bs/6070358-5-eng-US/intro-bs_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/intro-bs/6070358-5-eng-US/intro-bs_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/intro-bs/6070358-5-eng-US/intro-bs_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/intro-bs/6070358-5-eng-US/intro-bs_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/intro-bs/6070358-5-eng-US/intro-bs_full_2475.png 701w)
![image of torpedo ray](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-silhouettes/intro-torpedo/6118995-3-eng-US/intro-torpedo_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-silhouettes/intro-torpedo/6118995-3-eng-US/intro-torpedo_full_990.png 500w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-silhouettes/intro-torpedo/6118995-3-eng-US/intro-torpedo_full_1468.png 500w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-silhouettes/intro-torpedo/6118995-3-eng-US/intro-torpedo_full_1980.png 500w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-silhouettes/intro-torpedo/6118995-3-eng-US/intro-torpedo_full_2475.png 500w)
There are more than 500 shark species living today, all different shapes and sizes, from 6-inch dwarf lantern sharks to 60-foot whale sharks.
How Old Are Sharks?
Can you put these organisms in order, from the oldest to the most recent?
![1st](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/1st/6082541-1-eng-US/1st_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/1st/6082541-1-eng-US/1st_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/1st/6082541-1-eng-US/1st_full_1468.png 321w)
![1st](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/1st_1/6082624-1-eng-US/1st_1_full_495.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/1st_1/6082624-1-eng-US/1st_1_full_990.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/1st_1/6082624-1-eng-US/1st_1_full_1468.png 201w)
![2nd](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/2nd/6082540-1-eng-US/2nd_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/2nd/6082540-1-eng-US/2nd_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/2nd/6082540-1-eng-US/2nd_full_1468.png 321w)
![2nd](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/2nd_1/6082628-1-eng-US/2nd_1_full_495.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/2nd_1/6082628-1-eng-US/2nd_1_full_990.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/2nd_1/6082628-1-eng-US/2nd_1_full_1468.png 201w)
![3rd](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/3rd/6082545-1-eng-US/3rd_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/3rd/6082545-1-eng-US/3rd_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/3rd/6082545-1-eng-US/3rd_full_1468.png 321w)
![3rd](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/3rd_1/6082632-1-eng-US/3rd_1_full_495.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/3rd_1/6082632-1-eng-US/3rd_1_full_990.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/3rd_1/6082632-1-eng-US/3rd_1_full_1468.png 201w)
![4th](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/4th/6082549-1-eng-US/4th_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/4th/6082549-1-eng-US/4th_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/4th/6082549-1-eng-US/4th_full_1468.png 321w)
![4th](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/4th_1/6082636-1-eng-US/4th_1_full_495.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/4th_1/6082636-1-eng-US/4th_1_full_990.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/4th_1/6082636-1-eng-US/4th_1_full_1468.png 201w)
![5th](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/5th/6082553-1-eng-US/5th_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/5th/6082553-1-eng-US/5th_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/5th/6082553-1-eng-US/5th_full_1468.png 321w)
![5th](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/5th_1/6082640-1-eng-US/5th_1_full_495.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/5th_1/6082640-1-eng-US/5th_1_full_990.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/5th_1/6082640-1-eng-US/5th_1_full_1468.png 201w)
![6th](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/6th/6082557-1-eng-US/6th_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/6th/6082557-1-eng-US/6th_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/6th/6082557-1-eng-US/6th_full_1468.png 321w)
![6th](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/6th_1/6082644-1-eng-US/6th_1_full_495.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/6th_1/6082644-1-eng-US/6th_1_full_990.png 201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/6th_1/6082644-1-eng-US/6th_1_full_1468.png 201w)
![shark-like fishes](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/shark-card/6082605-1-eng-US/shark-card_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/shark-card/6082605-1-eng-US/shark-card_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/shark-card/6082605-1-eng-US/shark-card_full_1468.png 321w)
![shark-like fishes](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/shark-card_1/6082692-1-eng-US/shark-card_1_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/shark-card_1/6082692-1-eng-US/shark-card_1_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/shark-card_1/6082692-1-eng-US/shark-card_1_full_1468.png 1001w)
![coniferous trees](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/conifer-card/6082565-1-eng-US/conifer-card_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/conifer-card/6082565-1-eng-US/conifer-card_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/conifer-card/6082565-1-eng-US/conifer-card_full_1468.png 321w)
![coniferous trees](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/coni-card/6082648-1-eng-US/coni-card_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/coni-card/6082648-1-eng-US/coni-card_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/coni-card/6082648-1-eng-US/coni-card_full_1468.png 1001w)
![dinosaurs](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/dino-card/6082573-1-eng-US/dino-card_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/dino-card/6082573-1-eng-US/dino-card_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/dino-card/6082573-1-eng-US/dino-card_full_1468.png 321w)
![dinosaurs](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/dino-card_1/6082652-1-eng-US/dino-card_1_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/dino-card_1/6082652-1-eng-US/dino-card_1_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/dino-card_1/6082652-1-eng-US/dino-card_1_full_1468.png 1001w)
![flowering plants](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/flower-card/6082581-1-eng-US/flower-card_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/flower-card/6082581-1-eng-US/flower-card_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/flower-card/6082581-1-eng-US/flower-card_full_1468.png 321w)
![flowering plants](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/flower-card_1/6082660-1-eng-US/flower-card_1_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/flower-card_1/6082660-1-eng-US/flower-card_1_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/flower-card_1/6082660-1-eng-US/flower-card_1_full_1468.png 1001w)
![primates](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/primate-card/6082597-1-eng-US/primate-card_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/primate-card/6082597-1-eng-US/primate-card_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/primate-card/6082597-1-eng-US/primate-card_full_1468.png 321w)
![primates](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/primate-card_1/6082684-1-eng-US/primate-card_1_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/primate-card_1/6082684-1-eng-US/primate-card_1_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/primate-card_1/6082684-1-eng-US/primate-card_1_full_1468.png 1001w)
![modern humans](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/human-card/6082589-1-eng-US/human-card_full_495.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/human-card/6082589-1-eng-US/human-card_full_990.png 321w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/human-card/6082589-1-eng-US/human-card_full_1468.png 321w)
![modern humans](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/human-card_1/6082668-1-eng-US/human-card_1_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/human-card_1/6082668-1-eng-US/human-card_1_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/human-card_1/6082668-1-eng-US/human-card_1_full_1468.png 1001w)
Sharks are really, really old!
Sharks survived four mass extinctions. They even survived the one that killed most of the dinosaurs!
Sharks are really, really old!
Sharks survived four mass extinctions. They even survived the one that killed most of the dinosaurs!
![timeline showing from left to right shark-like fishes then coniferous tree then dinosaurs thenflowering plants then primates and finally omdern humans](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/timeline/6082613-3-eng-US/timeline_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/timeline/6082613-3-eng-US/timeline_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/timeline/6082613-3-eng-US/timeline_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/timeline/6082613-3-eng-US/timeline_full_1980.png 1601w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/timeline/6082613-3-eng-US/timeline_full_2475.png 1601w)
![timeline showing from top to bottom shark-like fishes then coniferous tree then dinosaurs thenflowering plants then primates and finally omdern humans](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/mobiletimeline/6082680-3-eng-US/mobiletimeline_full_495.png 440w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/mobiletimeline/6082680-3-eng-US/mobiletimeline_full_990.png 880w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/mobiletimeline/6082680-3-eng-US/mobiletimeline_full_1468.png 1201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/mobiletimeline/6082680-3-eng-US/mobiletimeline_full_1980.png 1201w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/timeline-sort-game/mobile/mobiletimeline/6082680-3-eng-US/mobiletimeline_full_2475.png 1201w)
What Makes a Shark a Shark?
Click on a body part to learn more.
![](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-anatomy/6068373-3-eng-US/shark-anatomy_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-anatomy/6068373-3-eng-US/shark-anatomy_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-anatomy/6068373-3-eng-US/shark-anatomy_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-anatomy/6068373-3-eng-US/shark-anatomy_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/shark-anatomy/6068373-3-eng-US/shark-anatomy_full_2475.png 1801w)
How do sharks sense their prey?
![shark artwork showing brain receptors](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_2475.png 1801w)
NOSTRILS
Shark nostrils are used only for smelling, not breathing.
INNER EAR
Unlike humans, sharks can detect the direction of low-frequency sounds to locate prey.
BLOOD ON THE BRAIN
Shark brains have an extra-large area devoted to scent, helping them smell a drop of blood diluted more than a million times.
![flat diagram of shark brain](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_990.png 901w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_1468.png 901w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_1980.png 901w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_2475.png 901w)
SIXTH SENSE
Sensors in the snout called ampullae of Lorenzini help sharks detect electromagnetic fields that reveal prey. Some sharks can even sense Earth’s magnetic field.
![photo of shark snout showing dots that are receptors](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_2475.png 701w)
Why are sharks such good swimmers?
![anatomical diagram of shark liver, spine, and fins](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_2475.png 1801w)
![orange graphic of shark and plane](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_990.png 900w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_1468.png 900w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_1980.png 900w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_2475.png 900w)
FIXED FINS PROVIDE LIFT
Shark pectoral fins don’t flap—they are stiff, like the wings of airplanes or hydrofoils. When sharks swim, these rigid fins provide lift, while the tail provides thrust.
![orange graphic of oil and water separating in bottle](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_495.png 450w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_990.png 450w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_1468.png 450w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_1980.png 450w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_2475.png 450w)
OIL-FILLED LIVERS
Unlike most fishes, which use an air bladder to keep from sinking, sharks have a huge, oil-filled liver. Unlike air, oil remains buoyant under high pressure, allowing sharks to swim in a wide range of depths.
Oil is less dense than water, which is why the oil rises to the top when you make salad dressing. Some shark livers contain 30 gallons of oil, which helps keep them from sinking.
![transparent graphic comparing swim speeds of shark and human](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_1468.png 1301w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_1980.png 1301w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_2475.png 1301w)
POWERFUL TAIL
In many sharks, the top of the tail is longer than the bottom. The skeleton extends into this large upper fin, providing more power for swimming.
How can sharks go so long between meals?
![illustration highlighting shark intestines](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_2475.png 1801w)
EXPANDABLE, ACID-FILLED STOMACH
A shark’s stomach acid is so strong it can dissolve shells and bones. The stomach expands to store food until it is slowly digested.
![three yellow icons; one fish skeleton, one seashell, and one turtle shell](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_495.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_990.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_1468.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_1980.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_2475.png 300w)
SLOW, EFFICIENT DIGESTION
Long, spiral intestines slow digestion and increase the surface available to absorb nutrients, making meals last a long time.
![scan showing the spiral structure of shark intestines](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_2475.png 701w)
How do sharks reproduce?
![illustration of shark highlighting its claspers](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_2475.png 1801w)
EGGS OR LIVE BIRTH?
Some shark species lay eggs—but some give live birth. What makes shark reproduction unique is that all sharks use internal fertilization.
![Illustration showing baby shark in egg case](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_495.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_990.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_1468.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_1980.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_2475.png 300w)
CLASPERS
Unlike most fishes, sharks fertilize their eggs inside their bodies. The male inserts sperm into the female with organs called claspers.
![photo of shark with claspers under its body](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_2475.png 701w)
Do sharks have to swim to breathe?
![illustration of shark highlighting its spiracle](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_2475.png 1801w)
![vector illustration comparing shark gills and fish gills](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_2475.png 701w)
SWIM OR DIE?
Many sharks must swim constantly to force water through their gills to breathe. That's because sharks lack gill covers, the hard flaps other fishes use to pump water through their gills. But some sharks can breathe while staying still. They breathe through a hole called a spiracle.
BREATHING WITHOUT SWIMMING
Some sharks and rays can draw water in through a hole called a spiracle and pump it over their gills. This allows them to breathe while motionless.
![photo of a shark identifying hole in its head](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_2475.png 701w)
How are shark teeth unique?
![illustration of shark that highlights teeth](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_2475.png 1801w)
REPLACEABLE TEETH
Shark teeth are replaced constantly. A single shark may shed 30,000 teeth during its lifetime.
![green graphic illustrating shark jaw](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_2475.png 701w)
TEETH FOR ARMOR
The hard, toothlike scales covering shark bodies are called dermal denticles, which means “skin-teeth.” They are so hard that sharkskin was once used as sandpaper.
![photo of shark teeth](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_2475.png 701w)
![](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/wmasas-mobile/6143902-2-eng-US/wmasas-mobile_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/wmasas-mobile/6143902-2-eng-US/wmasas-mobile_full_990.png 901w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/wmasas-mobile/6143902-2-eng-US/wmasas-mobile_full_1468.png 901w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/wmasas-mobile/6143902-2-eng-US/wmasas-mobile_full_1980.png 901w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/wmasas-mobile/6143902-2-eng-US/wmasas-mobile_full_2475.png 901w)
How do sharks reproduce?
![illustration of shark highlighting its claspers](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-diagram/6070528-3-eng-US/cl-diagram_full_2475.png 1801w)
EGGS OR LIVE BIRTH?
Some shark species lay eggs—but some give live birth. What makes shark reproduction unique is that all sharks use internal fertilization.
![Illustration showing baby shark in egg case](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_495.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_990.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_1468.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_1980.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-egg/6070544-3-eng-US/cl-egg_full_2475.png 300w)
CLASPERS
Unlike most fishes, sharks fertilize their eggs inside their bodies. The male inserts sperm into the female with organs called claspers.
![photo of shark with claspers under its body](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/cl-photo/6070532-6-eng-US/cl-photo_full_2475.png 701w)
How do sharks sense their prey?
![shark artwork showing brain receptors](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-electroreceptor/6068399-5-eng-US/sa-electroreceptor_full_2475.png 1801w)
NOSTRILS
Shark nostrils are used only for smelling, not breathing.
INNER EAR
Unlike humans, sharks can detect the direction of low-frequency sounds to locate prey.
BLOOD ON THE BRAIN
Shark brains have an extra-large area devoted to scent, helping them smell a drop of blood diluted more than a million times.
![flat diagram of shark brain](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_990.png 901w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_1468.png 901w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_1980.png 901w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-brain/6068886-3-eng-US/sa-brain_full_2475.png 901w)
SIXTH SENSE
Sensors in the snout called ampullae of Lorenzini help sharks detect electromagnetic fields that reveal prey. Some sharks can even sense Earth’s magnetic field.
![photo of shark snout showing dots that are receptors](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/er-img/6071028-4-eng-US/er-img_full_2475.png 701w)
How can sharks go so long between meals?
![illustration highlighting shark intestines](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-diagram/6070540-4-eng-US/si-diagram_full_2475.png 1801w)
EXPANDABLE, ACID-FILLED STOMACH
A shark’s stomach acid is so strong it can dissolve shells and bones. The stomach expands to store food until it is slowly digested.
![three yellow icons; one fish skeleton, one seashell, and one turtle shell](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_495.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_990.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_1468.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_1980.png 300w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-food/6070504-4-eng-US/si-food_full_2475.png 300w)
SLOW, EFFICIENT DIGESTION
Long, spiral intestines slow digestion and increase the surface available to absorb nutrients, making meals last a long time.
![scan showing the spiral structure of shark intestines](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/si-scan/6070536-5-eng-US/si-scan_full_2475.png 701w)
Why are sharks such good swimmers?
![anatomical diagram of shark liver, spine, and fins](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/liver-diagram/6070374-1-eng-US/liver-diagram_full_2475.png 1801w)
![orange graphic of shark and plane](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_990.png 900w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_1468.png 900w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_1980.png 900w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-fins/6070366-1-eng-US/sa-fins_full_2475.png 900w)
FIXED FINS PROVIDE LIFT
Shark pectoral fins don’t flap—they are stiff, like the wings of airplanes or hydrofoils. When sharks swim, these rigid fins provide lift, while the tail provides thrust.
![orange graphic of oil and water separating in bottle](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_495.png 450w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_990.png 450w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_1468.png 450w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_1980.png 450w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-oil/6070365-1-eng-US/sa-oil_full_2475.png 450w)
OIL-FILLED LIVERS
Unlike most fishes, which use an air bladder to keep from sinking, sharks have a huge, oil-filled liver. Unlike air, oil remains buoyant under high pressure, allowing sharks to swim in a wide range of depths.
Oil is less dense than water, which is why the oil rises to the top when you make salad dressing. Some shark livers contain 30 gallons of oil, which helps keep them from sinking.
![transparent graphic comparing swim speeds of shark and human](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_1468.png 1301w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_1980.png 1301w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sa-tail/6070370-1-eng-US/sa-tail_full_2475.png 1301w)
POWERFUL TAIL
In many sharks, the top of the tail is longer than the bottom. The skeleton extends into this large upper fin, providing more power for swimming.
Do sharks have to swim to breathe?
![illustration of shark highlighting its spiracle](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-diagram/6070524-3-eng-US/sp-diagram_full_2475.png 1801w)
![vector illustration comparing shark gills and fish gills](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-gills/6070516-3-eng-US/sp-gills_full_2475.png 701w)
SWIM OR DIE?
Many sharks must swim constantly to force water through their gills to breathe. That's because sharks lack gill covers, the hard flaps other fishes use to pump water through their gills. But some sharks can breathe while staying still. They breathe through a hole called a spiracle.
BREATHING WITHOUT SWIMMING
Some sharks and rays can draw water in through a hole called a spiracle and pump it over their gills. This allows them to breathe while motionless.
![photo of a shark identifying hole in its head](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/sp-photo/6070520-5-eng-US/sp-photo_full_2475.png 701w)
How are shark teeth unique?
![illustration of shark that highlights teeth](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_1980.png 1801w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/tee-diagram/6070508-4-eng-US/tee-diagram_full_2475.png 1801w)
REPLACEABLE TEETH
Shark teeth are replaced constantly. A single shark may shed 30,000 teeth during its lifetime.
![green graphic illustrating shark jaw](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-illo/6070500-3-eng-US/te-illo_full_2475.png 701w)
TEETH FOR ARMOR
The hard, toothlike scales covering shark bodies are called dermal denticles, which means “skin-teeth.” They are so hard that sharkskin was once used as sandpaper.
![photo of shark teeth](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_990.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_1468.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_1980.png 701w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/marine-biology/all-about-sharks/te-photo/6070512-4-eng-US/te-photo_full_2475.png 701w)
What Makes Sharks Swim Fast?
Sharks have evolved to swim faster and faster, to keep up with both predators and prey. Watch this video to learn about some of the adaptations that make them so speedy.
Where Do Sharks Live?
You can find sharks in all different parts of the ocean. Some, like bull sharks, live in different places at different stages of their lives. Some sharks always keep to the same region. But others move around.
Sharks move because of the time of year, or even the time of day. They might follow food or seek meeting places to reproduce—like blue sharks, which cross the Atlantic Ocean several times during their lives.
Image Credits:
bull shark, Flip Nicklin/Minden Pictures; Atlantic torpedo ray, Fred Bavendam/Minden Pictures; tiger shark electroreceptors, BluePlanetArchive/John Muhilly; spiral intestine, Samantha Leigh/California State University, Dominguez Hills; claspers, BluePlanetArchive/Masa Ushioda; spiracle, BluePlanetArchive/Nigel Marsh; dermal denticles, Eye of Science/Science Source; polar seas, Yva Momatiuk & John Eastcott/Minden Pictures; Greenland shark, BluePlanetArchive/Saul Gonor; Greenland shark underwater, BluePlanetArchive/Saul Gonor; Amazon River aerial, Pulsar Imagens/Alamy; peacock eye stingray, BluePlanetArchive/Franco Banfi; peacock eye stingray on river bottom, BluePlanetArchive/Franco Banfi; deep sea, Alexander Semenov/Science Source; chimaera, Science History Images/Alamy; chimaera close-up, David Shale/Minden Pictures; sand, Alex Mustard/Minden Pictures; southern stingray, BluePlanetArchive/Phillip Colla; southern stingrays on sandy bottom, BluePlanetArchive/Phillip Colla; coral reefs, Gary Bell/Oceanwide/Minden Pictures ; tasselled wobbegong, BluePlanetArchive/Tobias Friedrich; tasselled wobbegong on reef, Manfred Bail/ImageBroker/AGE Fotostock.
Video Credits:
sevengill shark, Charles Maxwell/NatureFootage; calcified cartilage tiles, J. Maisey/© AMNH; scalloped hammerhead, Tobias Meinken/NatureFootage; mako shark skeleton, Enault & Auclair/Kraniata Osteology; silky sharks attack sardines, Atlantic Edge Films/NatureFootage; spotted catshark, SimonSpear/Getty Images; sevengill shark, Charles Maxwell/NatureFootage; soupfin shark, Annie Crawley/NatureFootage; basking shark, Robert Harding Picture Library Ltd/NatureFootage; pelagic thresher shark, Klemens Gans/Blue Water Fascination; shortfin mako shark, Andy Brandy Casagrande IV/NatureFootage; great white above surface, Andy Brandy Casagrande IV/NatureFootage; great white below surface, Common Flat Project LLC.