|
понедельник, 29 января 2001 г., 19:19:02, you wrote:
Dear thermal people,
as I may suppose, living things are not ovens, so heating effects are
not simply linear, diffusive, described by heat flow models. Q - 10
coefficient is also too rough.
I'd not tell You smth. new supposing that practically all physical
influences on some organism first of all might call endocrine
consequences. Temperature - as well. If fishes are hiding in holes
from predatory birds then why - for example - young freshwater
browntrouts are standing in the sun for hours? Definitely not for
our pleasure. And then where are these awful birds? Everybody knows
that for example kingfisher'll never catch adult trout as too large,
but'll be happy to catch 7-10 cm. long specimen. And just this size
demonstrates itself just like on the beach.
I suppose that these young fishes have no idea
about birds - simply they need to expose their pineal glands under the
direct Sun to become mature ones and adults need shadow to be able to
push somatic growth. Riverine runs of Salmon has no natural exposure
as marine subpopulations - so they need to find Sun "artificially".
By the way lizards as all other vertebrates need
also not simply some "sum of heat" (as irons), but physiological
effects of insolation. Aquaculturists know this covering trout ponds
with black PCV films. In other case their trout'll feed poorly and
grow poorly. Really - what feeding when all thoughts is love:)
Click on "pineal gland" in any database and You'll find a lot about
electromagnetic energy transformation into neuroendocrine decisions -
especially in lower vertebrates. "Habitat patterns in relation to
temperature" are first of all the sum of neuroendocrine events
happening as a result of hormone production kinetics...... It's tooo
huge even to think about it - starting from genetic switch ons -
switch offs....... But definitely pineal literature'll help.
Have a nice day and best regards from sunny Crimea.
> Joseph,
> I physicist would know less than you about the physiology of fishes, a
> physiologist might have the information on the temperature regulation of
> fishes. It is an interesting question. I don't personally have any
> scientific information on thermoregulation in fish. But based on past fishing
> experience, rainbow trout (Oncorhynchus mykiss) and other freshwater fishes do
> have a habitat preference for deep holes in streams. The deep holes however
> may be preferred for other reasons besides temperature. The deep holes may be
> more important as rest areas, due to decrease stream flows in the area and
> they may provide better protection from predatory birds, etc. Undoubtedly
> shady areas are important refuges for fish in shallow slow moving streams, but
> are probably less important in major rivers which have high volumes of cold
> water. I hope I helped the discussion.
> James Stark
> Research fisheries biologist
> Alaska Fisheries Science Center
> National Marine Fisheries Service
> Seattle, WA
> Joseph Ebersole wrote:
>> Greetings,
>>
>> In my analysis of fine-scale patterns of habitat use by stream fishes in
>> relation to temperature, I've been confronted with a potential problem.
>> The temperature recording devices I use absorb solar radiation when
>> deployed in water <20cm deep, thus record water temperatures greater than
>> the actual ambient water temperature. Does anyone know to what degree
>> body temperatures of fish may be elevated by exposure to direct solar
>> radiation in shallow water? I've been assuming it's minimal, given
>> presumed ability of the fish to integrate various sources and sinks of
>> heat - and that the ambient water temperature (conduction) is the
>> predominate factor influencing fish body temperature. But I'm no physicist
>> by any means and might be missing something!
>>
>> I'd appreciate any replies, and will summarize all responses and post back
>> here.
>>
>> Thanks in advance,
>> Joe
>>
>> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>
>>
>> Joseph L. Ebersole 541-737-1979 (office)
>> Dept. of Fisheries and Wildlife, Nash Hall 104 [log in to unmask]
>> Oregon State University
>> Corvallis, OR 97331
>> _ .-^^-._ o
>> )~\.) @\ ,
>> ( \_ <
>> )/`-. _./
>> )_/
>>
>> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>
>> To leave the Fish-Sci list, Send blank message to:
>> mailto:[log in to unmask]
>> For information send INFO FISH-SCI to [log in to unmask]
>> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>
Modest Yu. Aleyev, Ph.D
Dept. of Phytobenthos and Algae Cultivation,
Institute of Biology of the Sothern Seas,
Natl. Acad. Sci. of Ukraine (IBSS NASU),
Nakhimov av., 3/2, Sevastopol, 99011,
Crimea, Ukraine
Tel: (38) (0692) 54 52 49
Fax: (38) (0692) 55 78 13 or 55 54 77
(for Dr. Modest Yu. Aleyev)
"Do or do not, there is no try". Yoda
><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>
To leave the Fish-Sci list, Send blank message to:
mailto:[log in to unmask]
For information send INFO FISH-SCI to [log in to unmask]
><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><> ><>
|
