do fish sleep?

Answer 1

No!

Answer 2

Most animals have some daily pattern of rest and activity, and in many species these daily cycles are similar to people running around during the day then lying down at night and doing nothing or sleeping. It is believed that fish are no different, although it is a controversial subject. Some fish keep very still, experiencing a quiet period (quiescence) that you might call sleep. Scuba divers often handle reef fish in the middle of the night without startling them and can even lift some species out of the water before they awaken. Tropical freshwater fish in home aquaria appear to be resting immediately after turning the lights on in a room that has been darkened for several hours. Unfortunately, fish have no eyelids so it is difficult to tell whether they are asleep or not.

Some fish undergo a yearly sleep cycle. They hibernate and their metabolic rate slows down. Although they do not hibernate like mammals, as environmental temperatures fall, their metabolic rate and activity decrease, and they go into a stupor and stop feeding. They usually adopt a position towards the bottom of the pond.

Some fish practice estivation, a state of torpor or dormancy in which they spend time during hot, dry periods to protect themselves from dehydration. The African lungfish buries itself in mud and survives the dry season protected by a cocoon of mud in the riverbed. Carp spend the winter partly buried in lake mud, and in tropical countries many fish sleep, or estivate, through the summer months when swamps and rivers dry up. Walking perch and lungfish bury themselves in mud, leaving only an airhole open, and breathe by means of their lungs. One of the gobies of the Ganges River delta digs a burrow and sleeps through the dry months with only the tip of its tail touching the water. It apparently breathes through its tail.

Some fish make elaborate preparations for sleep. In David Feldman's book When Do Fish Sleep?, a scientist describes the nightly ritual of a tired parrotfish that lives in reefs near shore. The parrotfish squeezes into a crevice on the reef. Once settled in, it begins oozing a jelly-like mucus, which forms a protective membrane over his body, and then he nods off into a deep sleep.

Some fish are motionless in the water during the night, while other fish, like rockfish and grouper, don't appear to sleep at all. They rest against rocks, bracing themselves with their fins. Some freshwater fish, like catfish, swim up under a log or river bank for shelter during the day.

Finally, some fish don't hide the fact that they take an occasional nap. One of the favorite habits of the clown loach, which has alarmed most new clown loach keepers in the past, is that of resting on the bottom of the aquarium on their sides. They appear as though they are dead or sick, but this is just one of the positions that they adopt when resting.

It's probable that fish do sleep in some form, whether slowing down or coming to a complete stop, whether hiding or doing it right in the open. But when they sleep the slightest ripple in the water will disturb them. Nevertheless, in some way they rest, just as we do.

Answer 3

Technically fish don't sleep. They don't hybernate either, they just relax. If you have a pet fish, try watching it, you will realise that it sometimes goes to the bottom of the tank and justs lays there. Its relaxing. Fish don't have eyelids either so it is unbelievable for a fish to close its eyes.

Answer 4

Diurnal fish go to rest in the dark - kind of like sleep. Nocturnal fish do not sleep - my synodontis, for example, are awake and active day and night.

Do fish sleep #671:
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Answer 5

Yes, normally just staying still near the top of the water, their fins moving gently with their body at rest. Any movement or change will wake them, though.

Answer 6

This question has been posted 671 times already...

They don't exactly "sleep".

They relax and regain energy.


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Answer 7

They rest to conserve energy! They don't sleep.

Answer 8

yes or either they conserve a lot of energy by not moving around at night.

Answer 9

yep mine floats on the top of the water like hes dead

Answer 10

I think they have to keep moving to stay alive

Answer 11

obviously, i have a goldfish and he/she sleeps .. & its kool cuz it happens at night..they don't move at all..just float in one spot