Do fish sleep? If so, then how?
356273
Fish sleep just like regular animals.  Thier basic motor functions still maintain, like movement.  Dolphins and other mammals shut down a half of thier brain at a time so they still come up for air.  Certain fish do this too because they don't pump water over thier gills, there needs to be motion to mover the water over them.  Hope that helps.
710541
I don't think porcupines hibernate, they will use dens, and tree hollows to sleep in.  I know they can climb because I once was out hiking and found a mother and her baby up high in a tree.
1004243
Maybe, but would that stop the fish from peeing?
38638
eat fish, good for brain power.
1021680
Depends on the kind of fish!\n\nTrouts need an extreme amount of oxygen, while some other fish could do with 10% of the amount...
518066
Put a fish in the water and see if it dies, if it doesnt then there is oxygen in the water. If it does then shame you have to buy another fish!!!
1095901
keep fishes\n\ngrow their feed like worms and bugs\n\nexpend your fish collection
680740
if its called a fish of any kind it has gills
393378
You could try to provide environmental conditions similar to the ones in their natural habitat. Some fish are nocturnal and will be sleep-like in the presence of daylight, or viceversa. \nThere are also anaesthetics for fish, such as clover oil or MS-222. You should consult an animal physiologist before administering them, though.
761847
Some of them are buoyant and sleep floating on the surface breathing air. Others can do what in humans is comparable to the "dead man's float" where you are under the water motionless then tilt your head back only, rise to the surface to breathe, tilt it back and resubmerge. Hippos can do this without ever waking up so I assume some marine mammals can too.
1080986
I can't say with any degree of certainty that fish are completely unphased by this experience, but for the most part the holes you make in their mouths by practicising "catch & release" will heal.  They will not affect the fishes ability to eat.  Whether a fish gets over the stress is hard to say!\n\nJust be sure to hold any fish you re-release under the water for a bit, moving it back & forth to get water running over its gills again. \n\nFish have very rudimentary nervous systems, so do not really experience "pain" the way a chicken or a gerbil might.
1141385
I tend to think a lot of us don't sleep much now and the time is, based on what I find when I am on the Internet, spent on our computers talking to others who can't sleep or don't. I like to write so I would be spending it in multiple areas of reading, writing and the computer. But I would also like to work in the yard and clean my vehicles. I don't think I could limit it to one activity all the time. It would get old pretty quick. You could fish all the time and not get bored??? Impressive!! Good question!!
314179
yes, sea otters sleep out in the ocean.  often they will wind themselves in strands of kelp to keep from drifting while they are asleep.  is this tool-using?  i would say yes.\n\nmost of the other species of otter (there are about a dozen species of otter world-wide, including some that can be over six feet long) sleep in dens built into the banks of rivers or lakes.
1071413
I own cows, and let me tell you, they do not sleep standing up. If you go out at night and see one standing up, believe me it is a wake, and a cow maybe laid back, but if you tick it off (most of all the bull) it will hurt you, and believe me they can really hurt.
711162
ants do sleep, or at least have a stage where they respond noticeably worse to external stimuli and are inactive. You just don't see ants sleep because they do that in their nest, not outside. You don't see many people sleep on the streets either, do you?\nWhy we sleep is a still unsolved and very intriguing question. Especially for something that essential. Clear is that people (or animals) can even die for lack of sleep. As it is a complex subject look up more details at the link below.
43450
Depends on your lifestyle. Do you have the time to take your dogs for walks, let them use the bathroom, wash them, etc.? Fish are okay if you miss a couple of feedings or water changes. You can hug a dog. Can't really hug a fish.
182101
i think they sleep. but they dont close their eyes. i think whent they remain still for a long time it means that they are asleep