Do sharks sleep?

Question

Will you answer this on a need to know basis? I need to know.

Answer 1

At least some sharks sleep.  I scuba dive and have seen Nurse Sharks and White Tipped Reef Sharks asleep.  At least, they are lying on the bottom (usually under a piece of coral or rock), with their eyes closed.  That is close enough to my definition of sleeping.

Answer 2

Yes and no. Beats me.

Answer 3

No.

Answer 4

Yes of course sharks sleep!!

Answer 5

Yes, it does.

I saw this on National Geographic

Answer 6

they would die if they slept like humans do because they cant gulp water in... they have to constantly swim around.

they can go to "power saving mode" though....

Answer 7

No they have to constantly swim or they'll sink to the bottom and die.

Answer 8

That's a great question.

Answer 9

Some do, most don't. The Nurse shark is an example of a shark species that sleeps. It has it's nap in daytime. You can find them under rock overhangs or in small caves. I've crept up to 10 footers having a doze. They wake at night and hunt the reef.

Most other species, however , have to move to survive, so sleep is not an option.

Answer 10

course they do--on water beds! (Sorry, I couldn't resist!) Actually, this question has caused a big debate among scientists. It was commonly believed that all sharks need to constantly swim in order to breathe (Talk about sink or swim!) The movement allows a continuous flow of oxygen-rich water through their gills. It's true that many sharks need to be permanently on the go, but that doesn't mean they can't rest at the same time.

It's just that sharks don't sleep the way you or I do. Sharks can't exactly snooze the night away in a bed or nest, but they do slow their brain functions down and just chill. Scientists describe this fishy state as kind of like daydreaming. It's also been discovered that some species, like nurse sharks, have openings behind their eyes--these are called spiracles--that force water through their gills, allowing them to stay still and hang out in one place, such as a cave.

Answer 11

No. They have no swim bladder as do bony fishes. So if they sleep they sink to the bottom.

Answer 12

no