Re: growth rate of fry and water changes

[Jim Atchison <jim@atchison.com>]

ALEX PASTOR wrote:

> Ken Laidlaw Wrote:
>
> >Well, without conducting this test I'd say that fry fed
> >well in a tank with plentiful water changes will grow
> >faster.
> >Ken.
>
> Let's not speculate.  That's the way others like CNN and the
> newspapers earn
> a living.  I tend to lean very heavily in your direction but....(heavy
> duty
> water changes is how all the big breeders everywhere maintain their
> tanks)...

and alot of the small breeders do the same...size has little to do with
it.

> hey let's see what happens with apistos.

...well then perhaps we can not change or add water for a year and see
what happens...I'd guess (speculate) that the water would dry up.

> There are enough people
> out there with lots of tanks and lots of fry.  The only thing stopping
> them
> is inertia.

...or perhaps common sense.If I've ever run into a test that didn't need
to be done...this is it. It has been done with other fish many times...I
did one like this with guppies in the late 60s.
Good grief...and when you get done with the rather unscientific
methology and someone asks you if you wieghed the food and calculated
the mass of the fish and contolled the temperature and took into
consideration that water evaporated (insert your choice of many
questions)...then what?

Having just completed a 20 pair study of barometric pressure and egg
production...I can tell you these seemingly little tests become huge
burdens and a bit less than enjoyable to most hobbyists...and like the
test I just completed, someone always hates the results and challenges
the validity of this or that.

Try counting eggs from 20 pair of killifish every day or 3 months.

If you want to study something that might yield results that we don't
already know...try studying the effects of temperature on the metabolic
rate and see if the fish grow faster in warmer water...and then do the
offspring of said faster growing fish (assuming they are)...are those
offspring as strong as the grandparents or do the following generations
lose something in the faster growth (assuming they do of course).

BTW, the study on the barometric pressure resulted in preliminary
results (we're studying the process for critical flaws)...the pressure
went down and the next day's egg production was down...the pressure went
up and the next day's egg production went up...yes, I have reread what I
typed...down=down and up=up...just the opposite of what people have said
would happen...

My never ending $.02 worth,
Take care,
Jim
--
High Prairie Farms
Freshwater Aquarium Fishes
San Rafael, California
415-472-7294 (phone)     415-472-7971 (fax)
http://www.atchison.com/highprairiefarms.html
LIVE FOODS!  http://www.atchison.com/live.htm



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