I heard a story once about pelargic sharks in public aquariums having
trouble because they could not get enough sleep. Apparently large
pelargic sharks sleep on the swim by slowly gliding down into the depths
and are woken up by pressure increase or the bottom. In an aquarium,
(bigger than rainbowfish size) they can't get enough sleep because they
bump into the bottom before they have nodded off properly.
I don't know if that is true but it sounds good.
Dave Wilson
Darwin
--------------------------------------
>Matthew Stanton wrote:
>>
>> Dear RML,
>>
>> Is there any adverse effect of fish never experiencing the dark?
>
>If uniformly illuminated, 24/7, yes! I have sterilized even guppies, that
>way.
>
>>
>> Do fish need sleep?
>
>Yes, most do.
>
>> If so can they get it when there is always a light on?
>
>Yes, if it dims way down.
>
>>
>> A new security light system has been installed in my office which keeps a
>> small amount of light on some of my work fish tanks all night. Should I be
>> concerned?
>
>I doubt it. If the amount is small, they will still get their sleep.
>
>Remember, tho, that free advice is worth every penny! ;-)
>
>Wright
>
>--
>Wright Huntley, Fremont CA, USA, 510 494-8679 huntleyone at home dot com
>
> "DEMOCRACY" is two wolves and a lamb voting on lunch.
> "LIBERTY" is a well-armed lamb denying enforcement of the vote.
> *** http://www.self-gov.org/index.html ***