16-17" Certified Female Nisai Omosako Shiro Utsuri

[Super Kindai]

Junichi, thank you for your explanations, very interesting post.

Lam, great idea to take vent pics.

Omosako Nisai. 18-19"+, Female guaranteed....

[farne230]

Junichi-san, are these omosako nisai SU for sale?
Bob

[Super Kindai]

Junichi-san, are these omosako nisai SU for sale?
Bob

Yes, it was, Bob-san. a few my friends (in Japan) bought a few of them at the past Spring.

[mystery.koi.expert]

I'm giving up on this shiro because of the yellow, so Lam is buying it from me as a gamble. I think it will improve but I don't know how much. I have a sibling of this fish in the same pond who has remained bone white all summer. So no, I can't explain and don't want to postulate. Heavy feeding, sunlight, genetics, sex, sexual maturity, all may be factors. Omosakos in particular can change a lot, and this fish has enough positives to make it worth watching. But I had to make some cuts.

I think you'll find that even when buying "Omosako" Shiro's directly from the farm, you will find that in the two main handpicking ponds for Tosai there are two, three and sometimes four bloodlines in the one pond. Each of them behave differently as Tosai, and each of them behave different as Nisai, and each of them...ad infinitum.

As for the first SU that is yellow-ish, I reckon that Jeff has given up a nice koi there, so he must be a very generous guy indeed. This koi will more than likely take a couple of years to regain white shiroji, and probably will never be crystal white, but the sumi config., body shape, and head all indicate this will be a good koi.

The second SU which has lost its Sumi...apart from one spot. I would say look after it well for a year, and see how things go...sometimes, just sometimes these all white Shiro's can have sumi which comes back. If it does come back, it will not be as nice as it was before, and may be spotty, but at least it will be B&W again!!! ;-)

Takehiro from Omosako Koi Farm always looks for two main things in his koi, body and pattern. But even he says pattern can change so much, even in three yr old koi. I would say for beginners when first buying a new SU, look for a nice body, THEN find a pattern that attracts you. But beware, patterns, much the same as investments on the stock markets, may go up as well as down!!! :-) Having said that a bad pattern will never become good, but a good pattern may become bad!!!

[JayInOz]

Looking forward to seeing those vent photos! Preferably with some notes on what exactly we need to be looking for S.K. how rare is it for male koi to change into female? Here in Australia several of our native fish species are male at first but change into female when they reach a certain size. (By law fishermen must return large specimens to the water as they are the breeding age females) JayInOz

[Super Kindai]

Takehiro from Omosako Koi Farm always looks for two main things in his koi, body and pattern. But even he says pattern can change so much, even in three yr old koi. I would say for beginners when first buying a new SU, look for a nice body, THEN find a pattern that attracts you. But beware, patterns, much the same as investments on the stock markets, may go up as well as down!!! :-) Having said that a bad pattern will never become good, but a good pattern may become bad!!!

Omosako brothers are not same as Dainichi's brothers......as you may know, there are a quite difference between Takehiro and Takeyoshi in terms of koi knowledge & their eyes. (just a friendly advice.)

[Super Kindai]

Looking forward to seeing those vent photos! Preferably with some notes on what exactly we need to be looking for S.K. how rare is it for male koi to change into female? Here in Australia several of our native fish species are male at first but change into female when they reach a certain size. (By law fishermen must return large specimens to the water as they are the breeding age females) JayInOz

To male koi change into female is not rare at all. I don't know well about a situation in the US but that's happening in hobbyist ponds, dealer ponds and breeder ponds everywhere in Japan. LOL,, I have heard that it is caused by Estrogen as endocrine disruptor and it has been a social problem because there have been many similar observations on various fish other than koi in the natural environment.

[CHICHI]

Male Fish Changing Sex

The Environment Agency has publicised the results of a study into the effects of pollution in our rivers including the Wey and has made a startling discovery. A third of male fish in English rivers are changing sex due to 'gender-bending' pollution.

Female hormones primarily from the contraceptive pill and HRT are being washed into the rivers after coming through the sewage treatment process intact and have so affected fish stocks that a significant proportions of male fish are now capable of laying eggs.

The study looked at the health of 1,600 roach in 51 rivers and streams. Tests showed that males had developed female sex organs and were producing eggs, with a marked deterioration in the sperm producing capability of the fish affected. Female fish were also producing abnormal eggs.

"Effects like a change in how many males can contribute to the population can change the genetic structure of the population," said Professor Tyler of Exeter University. 'In five years' time, the whole system could go belly-up. There is a soup of oestrogen compounds, all with different degrees of potency and they are interactive in their effects - if you add them together, you add there are additional effects. This soup of oestrogen is responsible for causing these changes to the fish. It is abnormal. These fish should be male or female. The fact that we have got such a large proportion right across the country is not right."

Previous studies had found similar effects on cod, trout and flounders.

http://marine-life.suite101.com/arti...ish_change_sex

[APOLONASGR36]

Anybody has those vent pictures? I would like to know what the male / female shape is supposed to look like.

[CHICHI]

Anybody has those vent pictures? I would like to know what the male / female shape is supposed to look like.

Found these over here ..

[JayInOz]

OK Chichi- so one of those is a male....... I can sex snakes- fish are still a problem JayInOz

[CHICHI]

OK Chichi- so one of those is a male....... I can sex snakes- fish are still a problem JayInOz

I didn`t Post which so that members could vote just for Fun the way the Thread transpired over here

[Jeff Speck]

first is male, second female

[CHICHI]

first is male, second female

http://www.koiquest.co.uk/forum/view...male+or+female

[APOLONASGR36]

Thanks Chichi!!

[JayInOz]

Thanks Chichi. That Pommie site looks interesting! JayInOz

[CHICHI]

Thanks Chichi. That Pommie site looks interesting! JayInOz

It Is