Do fish sleep?

[cesarbird]

Greetings Cecil. Hello everybody else!

I´ve had this question for ages:

Do fish sleep? :o :o

This main question triggers other second-order questions:

• If they do, do they close their eyes and lay down on the ocean bed?

• Is this the reason why the bottom of the ocean is called “ocean bed”?

• If they do sleep, for how long?

Thanks to all the knowledgeable people for letting me know!

Cesar
Frankfurt, Germany

[Annie-Xmas]

A quick Google reveals all:

How do fish sleep

Yes fish sleep. But it’s not sleep as we know it. They don’t have eyelids to close, they sometimes do it during the day, they don’t show the characteristic brainwave patterns like REM sleep seen in humans, and some, including most sharks have to keep swimming in their sleep.

But fishes do have a period of reduced activity and metabolism which seems to perform the same restorative functions as nocturnal sleep does in humans. Some are more obvious about it than others and actually rest on the bottom or in coral crevices, and parrotfish secrete a mucus “sleeping bag” around themselves before they go to sleep. If you get up quietly in the middle of the night you will find your goldfish in an almost trance- like state, hovering near the bottom of the tank making just the minimum correcting motions with its fins to maintain its position in the water column. If you put food in when they’re like this they take noticeably longer than usual to respond, as if they have trouble waking up.

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[njtt]

@cesarbird

• If they do, do they close their eyes and lay down on the ocean bed?

Generally, no.

@cesarbird

• Is this the reason why the bottom of the ocean is called “ocean bed”?

No. But…: Lava pillows on the ocean bed.

[74westy]

The fishes sleep with Luca Brasi.

[Dingbang]

Mine do “sleep” in every sense of the word except for closing their eyes (because they can’t). I have a tank full of African cichlids, and if you go in the room at night after the lights are off for the evening, they’re all bedded down. Most of them will actually be resting on the bottom, or on a rock or piece of driftwood, often nestled into a cozy spot. Others will be just floating but stationary. They’re clearly in a deep rest.
I’ve noticed that the older fish will nap during the day, usually in the same place, such as a nice depression in the driftwood. They’ll be lying there quietly until you walk by and disturb them. Unfortunately I’ve noticed that this daytime napping is a sign that the fish is quite old and won’t around much longer.

[Ludovic]

@74westy

The fishes sleep with Luca Brasi.

In Soviet Russia…