Does a fish sleep???

Question

My daughter needs to know for school. Thanks

Answer 1

Most all fish spend time in an energy-saving state that can be called
"rest", and we might even call their behavior "sleep", though it is probably
different than "sleep" in most land
animals. Many fish, like Bass and perch, rest on or under logs at
night. Coral reef fish active in the day, hide and rest in crevices
and cracks in the reef to avoid being eaten at night.
The resting behavior of fish is very different from their behavior the
rest of the day. Many minnows, for example, which are very active in
schools during the day, scatter and remain motionless in shallow
water at night. Many fish "rest" or "sleep" during the day and are
active at night instead, but almost all fish sleep.
There are some animals that never stop swimming, like many species of
shark, however, they HAVE to keep moving to push water through their mouths
in order to breathe, and they may still sleep while moving,
we just don't know yet.

Answer 2

Do fish sleep?


It all depends on what you mean by sleep. My dictionary says that sleep is a period of rest in which the eyes are closed and there is little or no thought or movement. That is, sleeping means closing your eyes and resting. The first thing we notice is that most fish don't have eyelids (except for sharks). Also, while some deep ocean fish never stop moving a great many fishes live nearly motionless lives and many do so on a regular diurnal/noctural cycle, some active by day others by night.. So we can't generalize and say that all fish sleep like we do. But most fish do rest. Usually they just blank their minds and do what we might call daydreaming. Some float in place, some wedge themselves into a spot in the mud or the coral, some even build themselves a nest. They will still be alert for danger, but they will also be "sleeping."

Answer 3

This is a complex question with no simple answer. Deciding if a fish is asleep depends on many factors, one of which is the definition of sleep.

In humans, the transition to sleep (or even closing the eyes) involves specified changes in the pattern of brain waves in the area of the brain called the neocortex. Fishes don't have the same degree of neocortical development as mammals and thus don't display these brain-wave patterns associated with sleep (view figure of a shark brain). So, as far as brain-wave patterns go, fishes don't sleep.

If, however, you define sleep as a combination of a reduced metabolic rate, slowed physical activity, lowered response to stimuli and the assumption of a resting posture, then many fishes do sleep. Perhaps the best-known 'sleepers' are the parrotfishes (family Scaridae). Many parrotfishes find a suitable spot on the seafloor and secrete a mucus envelope in which they spend the night.

Such fishes normally swim away from a diver by day, but can easily be approached and even gently handled at night. Many fishes, however, seem not to sleep. Pelagic (glossary) species such as tunas and some sharks never stop swimming. One theory suggests that during sleep, sensory information (predominantly visual) gathered during the day is processed to form memories. Fishes that swim constantly in blue oceanic waters receive little 'unusual' visual input and require less 'memory-processing time' and thus need no sleep. This is supported by studies on several species of blind fishes that live in caves. These sightless fishes do not sleep.

Answer 4

Yes when fish lie lifeless around a dark corner in there tank this is them sleeping they sleep with there eyes open and only usually sleep for 3 hours.

Answer 5

I used to have a fish tank, they do sleep but they dont have eye-lids so they just 'sit still' floating in the water with their eyes open, fish don't usually sit still for long unless their interested in something or sleeping ;).
Good luck ;)

Answer 6

Yes fish sleep.Parrot fish who live in coral spin themselves a mucus covering that they sleep in.Its quite strange because they can't close thier eyes. Imagine trying to sleep with your eyes open!

Answer 7

No, fish have two brains. The first one works in the morning and the other at night.

Answer 8

I have a pond with goldfish in it. At night they just stay very still, half way between the top and the bottom and their bodies are tilted down slightly, with their heads towards the bottom.

Answer 9

Hi

yes they do, different way of sleeping but they do!:

http://www.newton.dep.anl.gov/askasci/bio99/bio99047.htm

Hope she gets a gold fish for her next brithday if shes completes the question properly!

all the best!

Answer 10

Yes. I once had a guppy which actually slept on its side at the bottom of the aquarium... Unsuprisingly, it died.