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Author Topic: How do fish sleep?  (Read 56590 times)

Make it Lady

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How do fish sleep?
« on: 18/07/2008 19:10:00 »
They have no eye lids and are constantly swimming so how do they sleep if at all?

DoctorBeaver

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How do fish sleep?
« Reply #1 on: 18/07/2008 19:50:08 »
Like this...


Make it Lady

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How do fish sleep?
« Reply #2 on: 18/07/2008 19:51:32 »
Twadle!!!

DoctorBeaver

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How do fish sleep?
« Reply #3 on: 18/07/2008 19:53:03 »
 ;D

Make it Lady

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How do fish sleep?
« Reply #4 on: 18/07/2008 20:03:05 »
Anyone got a serious answer. My goldfish can't nod off and is counting Neileps.

atrox

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How do fish sleep?
« Reply #5 on: 18/07/2008 20:06:59 »
Yes, fish do sleep.
But with their eyes open. And not all of them swim around all the time.. just have a look in an watertank at night with fishes which are active at days. They are literally just hanging around, dont move much. I think most freshwaterfish rest like that.
Some fishes (like the parrotfish/Scarinae) rest between rocks, producing a bubble of slime around their body, to be scentless and not been found by the predators. Some sharks in coral reefs rest in big caves (or somewhere where is a lot of current..), where the oxygen-level is higher than in the surrounding ocian ...so they donīt have to move, but can really rest on the ground. But in fact, most sharks have to constandly move their body, to flood fresh water (not freshwater ;-) ) throught their gills. I read somewhere, that a great white shark have swim with at least 3 km/h (donīt know how much this is in miles per hour) all the time to get enough oxygen.

cu
aj

DoctorBeaver

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How do fish sleep?
« Reply #6 on: 18/07/2008 20:16:48 »
Sharks don't sleep as such. They just rest.

They also have the ability to shut down each hemisphere of the brain separately. Plus, the Central Pattern Generator that co-ordinates their swimming movements is located in the spinal column, not the brain. This means that even if the shark is completely unconscious, it can still swim.

Make it Lady

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How do fish sleep?
« Reply #7 on: 18/07/2008 20:29:31 »
Wow, now that is more like it.

atrox

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How do fish sleep?
« Reply #8 on: 18/07/2008 20:34:48 »
sleeping/resting sharks in such a cave I mentioned
http://www.youtube.com/watch?v=4XsWK65CqP4

and sleeping parrotfish
http://www.youtube.com/watch?v=muYmbq3LpZM

DoctorBeaver

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« Reply #9 on: 18/07/2008 21:03:27 »
Wow, now that is more like it.

I know a bit about sharks.

DoctorBeaver

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« Reply #10 on: 18/07/2008 21:06:05 »
sleeping/resting sharks in such a cave I mentioned
http://www.youtube.com/watch?v=4XsWK65CqP4


Oooh - white tipped reef sharks. They're cute. Don't let them see the second video because they eat parrot fish (among other things).

atrox

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How do fish sleep?
« Reply #11 on: 18/07/2008 21:10:18 »
hehe... I allways like the...dogfish(?? .. smaller sharks) the most

DoctorBeaver

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« Reply #12 on: 18/07/2008 21:19:14 »
The spiny dogfish is indeed a type of shark - Squalus acanthias.

atrox

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« Reply #13 on: 18/07/2008 21:25:39 »
oh yes...google my friend told me, thats the right one....but pretty confusing.. in Germany we call it "Katzenhai" >> Catshark ... but eventually thats why i kept the common name in mind...

DoctorBeaver

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« Reply #14 on: 18/07/2008 21:33:06 »
No. This is a catshark...



There is a family of sharks known as catsharks - Scyliorhinidae. Strangely enough, many species in that family are known as dogfish.

The largest is the humpback cat shark, which can grow to 4m.
« Last Edit: 24/07/2008 14:22:58 by DoctorBeaver »

atrox

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« Reply #15 on: 18/07/2008 21:39:18 »
yeeeah...isnīt it cute  :X


ah...I see... dogfish are something else ... I meant the Scyliorhinidae/catsharks

uuuh...now its not that confusing anymore...you have both...dogfish and catsharks.... so are they chasing each other up the trees? ;)

DoctorBeaver

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How do fish sleep?
« Reply #16 on: 18/07/2008 21:57:04 »
Maybe the catsharks go up trees to get the parrot fish!  ;D

opus

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How do fish sleep?
« Reply #17 on: 23/07/2008 22:54:09 »
....on waterbeds ....?

Alan McDougall

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How do fish sleep?
« Reply #18 on: 24/07/2008 01:02:49 »
Just to add. Whales although not fish, are mammals like us have to switch off one side of their brain at a time to give eah side a rest.

The reason is they are not automatic breathers like us and have to consciously breath or die. So if they were to fall asleep like we do they would stop breathing and die.

Regards

Alan

omghalloz

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How do fish sleep?
« Reply #19 on: 14/01/2009 00:26:33 »
first of all, it depends on their species, fish can be very different when varying between species, if you look at mammals like whales, they are concious breathers, meaning that they 'decide' when to breath; they are able to shut down one side of their brain (allowing it to rest) and use the other half to control their movements (to continue surfacing to breathe).
for fish like sharks (yes, a type of fish), then the utmost important thing to realise is that they must remain moving in the water to push water through their gills thus allowing more oxygen in to breath; there is one theory that they sleep something like whales (see explanation above). sharks do seem to enter this 'half rest state' (something like a nap), having been observed to be less responsive during this state (i.e. less attentive to things going on around them, not actively hunting/searching for prey, appearing tamer to humans etc). also, since most predatory sharks (unlike the calmer nurse shark) have a main hunt at night, therefore it would be useless for them to cuddle up on the ocean floor for the night as they'd lay prey to other sharks!
for other fish, such as the common goldfish, the fish can be observed to enter a 'resting' state at the bottom of their tanks overnight and sometimes during the day, somewhat like a nap. wild fish such as the tropical varieties found on coral reefs can be observed to enter such a state while hiding between crags and holes to avoid being eaten at night.
as with most things to do with sleep, there is no determined answer about what exactly goes on in an someone's/something's brain, but many theories suggest that yes, fish 'rest' but do not enter an unconciousness that humans do while we sleep.

Don_1

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How do fish sleep?
« Reply #20 on: 15/01/2009 16:34:43 »
They go to the sea bed!

dentstudent

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How do fish sleep?
« Reply #21 on: 15/01/2009 16:36:27 »
They go to the sea bed!

Ah, yes. Welcome back Don! I see that you had a bumper crop of crap cracker jokes at xmas.

Don_1

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How do fish sleep?
« Reply #22 on: 15/01/2009 16:41:54 »
They go to the sea bed!

Ah, yes. Welcome back Don! I see that you had a bumper crop of crap cracker jokes at xmas.

Yes indeedy, get ready for a groan or two, or three, or four, or ..........

duckyboy1975

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How do fish sleep?
« Reply #23 on: 02/09/2009 13:59:08 »
The real answer is that scientists still don't completely understand the sleep cycles of fish...
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Don_1

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How do fish sleep?
« Reply #24 on: 02/09/2009 14:09:44 »
The real answer is that scientists still don't completely understand the sleep cycles of fish...
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