# do piranhas sleep?



## EMJAY (Feb 27, 2003)

just curious. im still a little new to the whole hobby.
i alwasy see my fish swimming around and im thinking don't these guys ever get tired?


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## piranha 13 (Feb 16, 2003)

Yes they do. They do when you turn the lights out and the room is dark. They don't have eyelids though so they sleep with they're eyes open.


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## smb (Jun 1, 2003)

yep, all fish sleep.


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## Young Gotti (Jan 29, 2003)

turn ur lights on after u've had them off for awhile and u will see that they were sleeping. My red's seem like they get pissed off when i turn the lights on.


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## SnowCichlid (Jan 10, 2003)

you will notice that their bellies are not so red and more white usually and that they seem not as responsive...


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## smb (Jun 1, 2003)

*My red's seem like they get pissed off when i turn the lights on.*

LOL yea, that's because they probably are. ( i know you know that, but had to say that anyways)


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## thoroughbred (Mar 14, 2003)

Reckoning said:


> yep, all fish sleep.


 how do sharks sleep being that htye cant stop moving?


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## o snap its eric (Feb 19, 2003)

I read somewhere that fish half sleeps. Half of their mind is sleeping while the other half is on alert incase another predator is stalking them.


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## maverick (Apr 17, 2003)

"you will notice that their bellies are not so red and more white usually and that they seem not as responsive"
i have noticed it


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## Young Gotti (Jan 29, 2003)

Certain species of sharks can stop moving and they sit on the bottom of the ocean and sleep.


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## piranha 13 (Feb 16, 2003)

Hmmm....Great White Sharks though can't stop moving or they die. Maybe they swim through the water while sleeping. Sorta like sleep walking only sleep swimming.


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## smb (Jun 1, 2003)

thoroughbred said:


> Reckoning said:
> 
> 
> > yep, all fish sleep.
> ...


Some do stop moving. I've seen on Discovery Channell, video of them laying on the bottom in groups.

*Great White Sharks though can't stop moving or they die.*

Maybe it's not in a suspended state like we do. Not sure.


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## Nethius (Feb 23, 2003)

"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."found here

"Because sharks rely on ram-ventilation -- that is, their forward swimming to push oxygen-bearing water through their mouths and over their gills -- this fact begs the question: do sharks sleep at all? Dolphins are conscious breathers, actually having to think about rising to the surface, opening their blowholes, and breathing. From Russian studies carried out in the early 1970's, we know that dolphins catnap in 2 to 3-minute stretches, actually shutting down one hemisphere of their brain at a time. From experiments carried out on a small shark called the Spiny Dogfish (Squalus acanthias), we know that the 'Central Pattern Generator' that co-ordinates swimming movements in sharks is not located in the brain, but in the spinal chord. Thus, it is possible for an unconscious shark to swim. There is even a possibility that the sharks' fore, mid-, and hind- brain shut down in sequence, resulting in the shark equivalent of sleep-walking."found here


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## smb (Jun 1, 2003)

Good link. Very informative.


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## Judazzz (Jan 13, 2003)

Anyone ever noticed how piranha's act like they're completely drunk when you wake them up in the middle of the night? They just swim around randomly, bumping into decoration, each other, tank walls. Looks pretty funny


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## Mizery (Apr 5, 2003)

i noticed when my redbellies sleep they stay suspended in one spot and tilt to the side slightly, kind of interesting.


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## Young Gotti (Jan 29, 2003)

They have their tail fins higher and their heads pointing to the bottom.


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## Sir Nathan XXI (Jan 29, 2003)

Mine go to sleep within 30 minutes of their lights going out on timer. Not sure how long they sleep, I would like to know that. They rest on the bottom usually or in plants, and get very pale as others say. If light goes on suddenly in the room, they act drunk and bump into things head on, not darting but just a gently bump like duuuuhh


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## piranha45 (Apr 8, 2003)

EMJAY said:


> just curious. im still a little new to the whole hobby.
> i alwasy see my fish swimming around and im thinking don't these guys ever get tired?


definitely. When you turn out the lights and its night time, you can wait 30 mins, then get up and turn on the aquarium lights, and all your fish will be suspended or sitting on the gravel, not moving at all.

Thats the best time to net them, if you have to.


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## Nethius (Feb 23, 2003)

they probably freak out cause the light hurts their eyes... just think if you were sleeping, and somene opened your eyelid, and put a bright light into your face, you'd probably freak out too. LOL


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## Judazzz (Jan 13, 2003)

Nethius said:


> they probably freak out cause the light hurts their eyes... just think if you were sleeping, and somene opened your eyelid, and put a bright light into your face, you'd probably freak out too. LOL


 But would you dash through your room like a madman?


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## JesseD (Mar 26, 2003)

LOL







. good point Judazz


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## Mr. Hannibal (Feb 21, 2003)

Of course they sleep but they can't close their eyes so you can't notice!


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