| I seem to have an entirely different take on this subject?
Tosai are all living creatures with 'genetic marching orders' regarding color, shape and size. And just as you can not grow a koi to be 8 feet long, you can not keep a fish at 5 inches all it's life without cruel and unusual conditions and lack of diet.
Some individual fish will be 34 inch fish and many individual fish will be 24 inches and some individual fish will be 20 inches. This is their genetic potential.
But potential may or may not be realized based on environment. A lower form of life, like a carp, is highly influenced by environment. This is true for two reasons-
1) Proximity and intimacy of environment- there are only two layers of cells ( in the gill) that separate the outside water quality from the fluids inside the koi and therefore the entire physiology and metabolic function.
2) Feedback- that is, the rebound effect that living koi produce on themselves in a closed pond system. Koi loaded in a closed system is an environmental factor but lack of maintenance is the real issue in crowding and NOT just numbers. Many of the breeders systems for instance look crowded but they are semi open systems with many gallons of water passing thru per day.
The factors for stunning are pretty well known:
1) poor diet and lack of protein
2) G.A.S. syndrome which in a word is 'Stress'
3) excess nitrates and pheromones
What the wacky middle men of Chiba , Kyoto and Hiroshima stumbled on the marketing idea of stunning koi for goldfish ponds, they tried and recommended the following:
1) find koi from the smallest breeding pair you can find ( genetic factor)
2) crowd the fish
3) feed very little
4) do not do water changes and always maintain nitrate as high as possible.
When the breeders finally realized that they could sell tosai for major dollars if they were oversized because the public would believe they would continue to grow that way they simply reversed the process of the bonsai conmen by:
1) finding the largest breeders they could
2) not crowding
3) over heatng to race the metabolism ( eternal summer syndrome)
4) feeding high calorie, high protein foods
5) semi open systems to keep metabolites near zero
But what we are confusing here is not TECHNIQUES to stretch or stun tosai as a species approach, but rather individual results when moving fish from less ideal conditions to better conditions. In other words, the removal of those environmental factors that lead to stress and metabolic poor performance so that genetic potential can be released/realized.
Stress is not something that passes in a few hours. Studies done on marine fish, a much weaker group of fishes, show that stress effects can last for months. Hard to see in a koi unless you move a large female from Japan and often you then realize that stress and ' settling in' can take upwards to a year! And often the beni and shiroji is never the same. But the linger effects on tosai is real also.
I have absolutely seen fish moved, even after age three, and watched them explode with growth in a better environment. It is as if the genetic potential was being sat on and now was screaming for expression. I have also seen it go the opposite way, in fact, more often the opposite way.
If anyone is interested, I was copy and past some of Momotaro's comments ( the growers growing master) about the experiment he did on a spawn of fish in which group A was wintered and group B was given hot house conditions and how the fish all fared over two seasons. The net effect was at any one moment in the year group B was ahead. But at the end of every summer in the mud, group A would catch up. Note, this is without stress factors.
With stress factors, group B would not have been allowed to 'catch up'. And this spread would be magnified over time. Especially in the 'wonder bread years' when the percentage of growth is higher than it is past age four or five. - JR |