do fishes sleep?

Question

im just wondering if fishes sleep do they?

Answer 1

I think they do. They cant close their eyes so it is hard to tell if they are sleeping.

Answer 2

hi there

Frequently Asked Questions
Do Fishes Sleep?

A Steephead Parrotfish 'sleeping' in its mucus envelope. This image was shot at night at a depth of 12m, Ribbon Reefs, Great Barrier Reef, Queensland, October 2003. View fact sheet for this species. View larger image.

Strange bedfellows! A Minifin Parrotfish (view fact sheet) 'sleeping' beside an Ornate Wobbegong (view fact sheet). This image was shot at a depth of 8m, Flinders Reef, Queensland, November 2003. View larger image.

A Parrotfish 'sleeping' in a crevice in the coral at Heron Island Bommie, Queensland, November 1998. Note the shrimp on top of the fish's head. View larger image. 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.

Having said all that, though, I did enjoy the simple answer of a young neighbour who told me with confidence that fish can't sleep because they don't have eyelids.

The text on this webpage is from McGrouther, M.A. 2003. Do Fishes Sleep? Nature Australia. Spring. 27(10):82.

Answer 3

I have owned fish like guppies and platys who lay on the bottom of the tank at night. I aways assumed that is the way they went to sleep. Either that or I had some really weird fish.

Answer 4

Hi! Fishes do sleep but they have no eyelids. Whenever you turn off the fish tanks light at night they usually lay on the bottom or hide. And that is when they sleep. This relieves stress from them and makes them have more energy when you turn the lights on! When I turn my fish tanks lights on they usually look tired and groggy at first kind of like us! Hope that helped!

Answer 5

Fish "relax" but they don't have the ability to close their eyes like mammals, birds and reptiles. They find a quite place and sort of let their guard down until that little lateral line tells them they need to pay attention.

Kev

Answer 6

To correct things a bit weather it's one fish or two it's still fish no s is needed to make it plural.

Answer 7

No, they party all night until they die. Of course, they sleep! They just go motionless (drifting, actually) with eyes open. You know, like you're in a boring English class. Hah!!

Answer 8

yes they do in there underwater lairs
they very rarely do but when one does they snore very loudly
thats how u gt tsunamis

Answer 9

they do...I think it's called a hypnotic state that they go into with their eyes open.