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I've always wanted to know: do fish sleep? I've never actually seen one sleep...
thought you might be interested in this... Being asleep can mean different things to different fish. Some fish and amphibians reduce their awareness but do not ever become unconscious like the higher vertebrates do. Fish have time periods when they become less aware of their surroundings but their brain waves do not change, and they do not exhibit REM sleep. They aren't quite asleep but they don't seem to be fully awake either.
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.
Yes and no. They do rest but they do not sleep as we think of it. Some of their mental function shuts down and they go into a kind of light nap. Most fish need to move every few seconds or they suffocate since the act of movement passes water over their gills and delivers oxygen to their blood.
I've ALWAYS wanted to know that haha , my dad has some goldfish, and I alwayswondered weather they ever went to sleep because you see them at the bottom of the tank sometimes very still but thats about it! :D haha
yes they do sleep they just dont sleep with there eyes clothes so it looks like they dont sleep
no. they don't have eyelids... so they can't close their eyes. they just float around
No they just rest
