do all living creatures require sleep? how would a shark sleep, they have to continue moving to breathe.??

Question

I know fish do not close their eyes because they have no eyelids, and i know some animals sleep very lightly and standing up, horses and elephants for example but I am curious about sharks which must keep moving in order to breathe and live and wonder if insects, spiders, etc. require sleep...

Answer 1

The nurse shark does sleep, and recent research shows that most sharks do sleep. They glide along and take a nap. Some sharks have to do this, because unlike fish their gills need a moving water source to work properly, but many sharks can stay put so they don’t suffer this problem. Some sharks even have opaque eyelids. We just don’t know enough about them to make a definitive statement for sharks on sleep.

According to Wikipedia: http://en.wikipedia.org/wiki/Hibernation
"For a couple of generations during the 20th century it was thought that basking sharks settled to the floor of the North Sea and hibernated. Tracking devices installed on 20 basking sharks in 2002 dispelled this hypothesis.

The epaulette sharks have been documented to be able to survive for long periods of time without oxygen, even being left high and dry, and at tempreatures of up to 26 °C. [1] Other animals able to survive long periods without oxygen include the goldfish, the red-eared slidder turttle, the wood frog, the bar-headed goose. [2] As a related side note, the French diver Loïc Leferme has the world record for diving to a depth of 171 metres on a single breath of air."

According to this Wikipedia Article: http://en.wikipedia.org/wiki/Sharks#Shark_sleep

"Shark sleep
It is unclear how sharks sleep. Some sharks can lie on the bottom while actively pumping water over their gills, but their eyes remain open and actively follow divers. The spiny dogfish's spinal cord, rather than its brain, coordinates swimming, so it is possible for a sleeping spiny dogfish to continue to swim while sleeping. It is also possible that a shark can sleep with only parts of its brain in a manner similar to dolphins.[17"

Words on us: http://www.wordsonus.com/babes/2006-08_shark-sleep.html
Has a good article on shark sleep. The article mentions that some sharks have eyelids and some stay put in a camouflage position, others can sleep on the move (like dolphins). If they have their eyes open it is hard to know when they are asleep.

Some sharks do sleep, other sharks may do it on the glide and others may sleep with only use part of their brain to sleep. We just don't know. We do know that sharks cover wide ranges and dive deeply and close to the surface; they use the entire sea. One species found off of California was tracked to Hawaii and back. They are a very successful species so there are so many types of sharks in the world and their requirement for sleep and how it is done can vary with each subspecies.

As a whole many animals sleep, some even hibernate as a strategy to get through the lean times of winter. If a human is deprived of sleep for a week or more then they start to suffer delusions and go insane. Mammals need sleep to survive, but each animal species differs and we may not know about much, if any, sleep they get. An example of how little we know about some animals is with the humble worm. For 120 years based on Darwin’s work we thought that worms ate all that was in front of them as they tunneled through the earth. Recently, a scientist discovered that they use their jaws to wedge open a crack and slip through the crack. They only eat what they want to eat. (Popular Science September 2006, article Top Ten Brilliant Scientists.)

So the question is still in debate.

Answer 2

many sea creatures, including some sharks, have gill covers that can move back and forth to push the water into their gills. because they have something to push water over their gills, they do not need to move all the time. take, for example, freshwater pike. they sit still until they find their prey, and when that moves close enough, the pike charges.

even then, with species that DO need to keep moving, they slow down, and sometimes stop for short periods of time. when you sleep, your breathing, and need for oxygen goes down, because you aren't burning as much energy as you were when you were awake.

Answer 3

Sharks do not sleep...most fish do not sleep so no not all lifeforms require sleep.

Some don't sleep but go into resting periods where they are not active but awake while some go into hibernation where they sleep for long periods of time...varies from animal to animal