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Lam Nguyen
10-19-2009, 05:58 PM
This is a 16-17" certified female nisai (16 mos old) Omosako Shiro Utsuri that I just purchased from a hobbyist in San Jose. What do you guys think? Any potential? Keeper for now or time to rehome? From what I know, she grew from 10" this spring to her current size of 16-17" on Saki Hikari. I don't know anything about the previous owner's pond water parameters.

Any of you have any experience with the yellow color? If so, then will it clear up or will the yellow stay? Is this yellow a sign of too much San Jose sunshine, water parameters, diet, liver issue, and/or sex? Will Manda Fu, Hi-Silk, and/or Sweet Potatoes help to clear up the shiroji? The certificate says female but I know that certificates can be wrong.

From what I know, the previous owner hasn't tried to sex her. Even if he tries, I don't how accurate it will be at this age and season. I can't tell from looking at the shoulders and pecs whether it is a male or female. I love the torpedo-shaped bone structure (pixs can be deceiving though:D:) and the balanced 1/3rd of pec depth motoguro. And the head. Who cannot adore that broad and beautiful head with eyes set shoulder-width apart and farther back towards the gill plates and a wide mouth. Do I hear jumbo, anyone?:D: And more importantly, while she doesn't have the checkered pattern and desired odome, IMO, her sumi is of very high quality with some Magoi influence. Now if they all come up at the same time and the yellow clears up, I may have myself a beauty!

I am somewhat concerned about the short leading ray on her right pec as well. At this age, I don't know whether that ray will grow back. Anyways, any opinion and/or feedback is much appreciated.:D:

Super Kindai
10-19-2009, 11:59 PM
Lam-sam, What is the fish' Oyagoi name.....Musashi, Panda, or Ebisu? Also, Don't you have more decent & detail pictures?? :D:

http://omosako.web.fc2.com/keito/news-japan.html

nguyen4
10-20-2009, 12:26 AM
Hi Lam fish look have good body structure, I not good on skin or color so let someones tell you about it. I like your fish. I have ones from last grow out contest. What happen now is a white fish, last night I finish a new Koi Nations and look back my fish picture. You know what happen? I just tell myself maybe it not come yet. This is her later picture:yes:

Lam Nguyen
10-20-2009, 12:44 AM
Lam-sam, What is the fish' Oyagoi name.....Musashi, Panda, or Ebisu? Also, Don't you have more decent & detail pictures?? :D:

http://omosako.web.fc2.com/keito/news-japan.html

Thanks for the link, Junichi-san. If I remember correctly, she is an offspring of Musashi. I will get more decent and detailed pictures as soon as she arrives later this week. Junichi-san, what do you think about the sex? The certificate says it's a female born in 5/30/2008 (same month and date as my daughter's date of birth:D:). And is the yellow concerning? Will the yellow improve with time? Have any of you seen koi with malfunctioning liver causing too much bilirubin resulting in the jaundice look?:D:

Lam Nguyen
10-20-2009, 12:50 AM
Hi Lam fish look have good body structure, I not good on skin or color so let someones tell you about it. I like your fish. I have ones from last grow out contest. What happen now is a white fish, last night I finish a new Koi Nations and look back my fish picture. You know what happen? I just tell myself maybe it not come yet. This is her later picture:yes:

Nguyen, I really like this Omosako shiro utsuri. Any idea who the oyagoi is? Also, what size and what age? Do you have any pixs of when you first bought her? Was she all white at tosai? I would keep this one for a long time, Nguyen. There might be a lot more surprises to come. If you don't have the patience to watch her develop, then she is welcome in my pond any time! Something tells me there's Panda influence!:D:

Jeff Speck
10-20-2009, 09:30 AM
Examples:

Lam Nguyen
10-20-2009, 11:38 AM
Thanks Jeff. Look at how much whiter the shiro got over a few month's time! There's hope!!!!! Now, gotta make sure it's a female.;)

broll
10-20-2009, 12:45 PM
Lam -

Great looking SU.

Jeff -
Is this yellowing phenomenon something that always (or very often) happens with female SU around the 10.5 month age marker? If so, can you explain (in words that will support your great visual examples) why? And is there another point later in development where if always (or very often) happens again?

Thanks,

bec

Jeff Speck
10-20-2009, 01:38 PM
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.

Super Kindai
10-20-2009, 01:49 PM
Thanks for the link, Junichi-san. If I remember correctly, she is an offspring of Musashi. I will get more decent and detailed pictures as soon as she arrives later this week. Junichi-san, what do you think about the sex? The certificate says it's a female born in 5/30/2008 (same month and date as my daughter's date of birth:D:). And is the yellow concerning? Will the yellow improve with time? Have any of you seen koi with malfunctioning liver causing too much bilirubin resulting in the jaundice look?:D:
I see...it's a Musashi....... If anything, the fish looks like a female but hard to tell by this pic only. the short "broken" leading ray on her right pec will not grow back in most cases. the yellow is concerning if it is a male, but is not concerning if it's a female with a skin texture of fine grains type. Not only SU but also Gosanke during a rapid growing season in mud ponds have most likely yellowish skin compare to winter season. According to Omosako's experiences & opinion, often yellow ones are better in future......:cool3:

>IMO, her sumi is of very high quality with some Magoi influence....
Ahh, Lam-san, this is a brand new & unique interpretation of sumi.....:eek1: :D:

Here is Omo's succeeded samples of 21 different fish. ( click to see large pics of each fish & progress)
http://omosako.web.fc2.com/process-japan.html

nguyen4
10-20-2009, 02:01 PM
How about my fish, SK?

Super Kindai
10-20-2009, 02:11 PM
How about my fish, SK?
It's a male, isn't it? :confused:

gcuss
10-20-2009, 02:15 PM
Lam,

Like Junichi, if it's a girl indeed, the yellow doesn't bother me. And she does have an outstanding head and bone structure going on.

Too much sumi for my personal taste, and would be nice to see a picture as tosai. I'm wondering if she showed kage type sumi then as well, or if it's on the move.

The leading ray on the pec is a little iffy. Of course, I'm not an expert but I would worry about it growing back...

You surprised me with this one Lam, good luck!

Grant

nguyen4
10-20-2009, 02:22 PM
Sorry i don't know how to sex my fish. But I think it is a female.

Super Kindai
10-20-2009, 06:15 PM
Sorry i don't know how to sex my fish. But I think it is a female.

I see.. :yes:,, It looks to me that the skin looks fine but not a great thru the pictures. In reality, a slightly bluish skin is preferable for its future sumi quality, unlike kohaku's white-pinkish type skin,. Also in reality, an immovable sumi (the sumi that is coming up & down at same place is fine) is better than a movable sumi here and there.....Sanke & Showa as well.

Russell Peters
10-20-2009, 06:18 PM
I see.. :yes:,, It looks to me that the skin looks fine but not a great thru the pictures. In reality, a slightly bluish skin is preferable for its future sumi quality, unlike kohaku's white-pinkish type skin,. Also in reality, an immovable sumi (the sumi that is coming up & down at same place is fine) is better than a movable sumi here and there.....Sanke & Showa as well.


Junichi, he is talking about his Hasegawa Kohaku in a different thread.

Super Kindai
10-20-2009, 06:23 PM
Junichi, he is talking about his Hasegawa Kohaku in a different thread.

:eek1: I think he is talking about the SU on #3 of this thread...maybe:D:

Russell Peters
10-20-2009, 06:25 PM
:eek1: I think he is talking about the SU on #3 of this thread...maybe:D:


Oops, sorry. I had 3 hours sleep last night and some beer.:rolleyes: i read the thread and forgot about that post.

Lam Nguyen
10-20-2009, 06:27 PM
Beer?! Did I hear beer?! Well, where's the beer?! Yes, I believe Nguyen is talking about his Omosako shiro utsuri in post #3.

The Hasegawa kohaku is not too shabby, though!

Lam Nguyen
10-20-2009, 09:54 PM
I see...it's a Musashi....... If anything, the fish looks like a female but hard to tell by this pic only. the short "broken" leading ray on her right pec will not grow back in most cases. the yellow is concerning if it is a male, but is not concerning if it's a female with a skin texture of fine grains type. Not only SU but also Gosanke during a rapid growing season in mud ponds have most likely yellowish skin compare to winter season. According to Omosako's experiences & opinion, often yellow ones are better in future......:cool3:

>IMO, her sumi is of very high quality with some Magoi influence....
Ahh, Lam-san, this is a brand new & unique interpretation of sumi.....:eek1: :D:
Here is Omo's succeeded samples of 21 different fish. ( click to see large pics of each fish & progress)
http://omosako.web.fc2.com/process-japan.html


Junichi-san, I will see if I can quote a section from the textbook KOI I that discussed Magoi-influenced sumi.:D:

Super Kindai
10-20-2009, 11:40 PM
Junichi-san, I will see if I can quote a section from the textbook KOI I that discussed Magoi-influenced sumi.:D:
Aha Lam-san, "Magoi-influenced sumi" was written in a book. :eek1:
Although I don't know about the textbook KOI, it is interesting to know how Magoi's brown-grayish, a sort of boke zumi, influence to a navy-blue based refine Shiro Uturi zumi in recent years...:yahoo:

broll
10-21-2009, 12:21 PM
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.

Got it.
Thanks Jeff.

bec

Steve Nguyen
10-21-2009, 04:20 PM
how much patient do you have? given the pond/water condition in the US, not sure I would gamble on this one.

Steve

farne230
10-21-2009, 09:30 PM
I read that yellowing may be hormone production in femal shiro's. :confused:
Bob

Lam Nguyen
11-02-2009, 03:38 AM
Here are more pixs of Kiiroogaru (translated Yellow Girl). She measures at 42cm (16.5 inches). And yes, it's a confirmed female.:D:

koi123
11-02-2009, 08:41 AM
It looks really nice but I do not understant why it is so yellow.

Jeff Speck
11-02-2009, 08:45 AM
Excellent pics, Lam.

Hirogoi
11-02-2009, 09:11 AM
I don't like it. I think it has a nice body, and I know shiros tend to brighten up, but these one just seems flat. No shine or luster.

Lam Nguyen
11-02-2009, 09:58 AM
It looks really nice but I do not understant why it is so yellow.

Yeah, not too sure either. But that is why Jeff let it go. Will gamble and give her a try to see if she will clear up.:D:

Lam Nguyen
11-02-2009, 09:58 AM
Excellent pics, Lam.

Thanks Jeff.:D: Let's see if I can clear her up and get some length on her.:D:

Lam Nguyen
11-02-2009, 09:59 AM
I don't like it. I think it has a nice body, and I know shiros tend to brighten up, but these one just seems flat. No shine or luster.

Hirogoi, that's exactly what I was thinking last night when I bowled her up for pixs. She doesn't seem to have the tsuya, or skin luster.

Jeff Speck
11-02-2009, 10:03 AM
Believe it or not, it has actually whitened up quite a bit now in the last month. I think you can see it was more yellow in my pic that Lam started the thread with. That was maybe 3 weeks ago.

Lam Nguyen
11-02-2009, 10:26 AM
Believe it or not, it has actually whitened up quite a bit now in the last month. I think you can see it was more yellow in my pic that Lam started the thread with. That was maybe 3 weeks ago.

Thanks Jeff. From physically comparing her from when she first arrived and when I took the pixs yesterday, I believe that she has whitened up some, but not a lot. Pixs can be deceiving and I think that I used more light exposure than you did. That's why it is so hard to judge from pixs and why I recommend physically looking at a koi before making a purchase.

Care to share the two shiros that you kept?;) I know that they will put this shiro to shame, but we are all learning here.:D:

Jeff Speck
11-02-2009, 11:42 AM
I told Lam that I bought several Omosakos this year, knowing I would only have the space to keep 2 or 3 into next growing season. So as a curiousity here are the two I'm keeping. The third one shown is listed somewhere in the trader forum, but I'm not opposed to keeping it another year also. I like the patterns, but there are pros and cons to each of them. I think Lam's has the best body for its age. #1 "Tejima" is my favorite but not certified female, #2 is a chagoi personality in a shiro body and I'm going to have a hard time keeping her from becoming a pot-bellied blimp, but very nice shiroji. #3 has excellent height on the body, but head is a little pointy and a lot of black. I basically stuck with these two (or three) because they are the most aggressive eaters, and the first two are now at 18 inches.

Jeff Speck
11-02-2009, 11:47 AM
Depending on the yellow issue, Lam's really could turn out to be the best IMO.

Super Kindai
11-02-2009, 02:12 PM
Hirogoi, that's exactly what I was thinking last night when I bowled her up for pixs. She doesn't seem to have the tsuya, or skin luster.

Generally speaking, a luster (or tsuya/teri) drops, once you use koi for a show or if koi are being shipped for some reason. and it takes for a while to regain a luster to same level. (If a koi does not have tsuya by nature, it won't back forever though. :D: )

Super Kindai
11-02-2009, 02:25 PM
I told Lam that I bought several Omosakos this year, knowing I would only have the space to keep 2 or 3 into next growing season. So as a curiousity here are the two I'm keeping. The third one shown is listed somewhere in the trader forum, but I'm not opposed to keeping it another year also. I like the patterns, but there are pros and cons to each of them. I think Lam's has the best body for its age. #1 "Tejima" is my favorite but not certified female, #2 is a chagoi personality in a shiro body and I'm going to have a hard time keeping her from becoming a pot-bellied blimp, but very nice shiroji. #3 has excellent height on the body, but head is a little pointy and a lot of black. I basically stuck with these two (or three) because they are the most aggressive eaters, and the first two are now at 18 inches.

#1 "tejima" looks a good SU indeed. I am wondering if there is no sign of a gender at all even 18" ?

Super Kindai
11-02-2009, 05:31 PM
Here are more pixs of Kiiroogaru (translated Yellow Girl). She measures at 42cm (16.5 inches). And yes, it's a confirmed female.:D:
Lam-san, Have you ever heard or read any books about the difference between a thick skin and a thin skin? and how does the difference effect for koi's appearance and its growth for the future?

Jeff Speck
11-02-2009, 07:15 PM
#1 "tejima" looks a good SU indeed. I am wondering if there is no sign of a gender at all even 18" ?

I haven't looked at the vent or tried for milt. I usually just wait until their second spring and see if they get rough and chase, and maybe check under the hood then.

Super Kindai
11-02-2009, 07:21 PM
I haven't looked at the vent or tried for milt. I usually just wait until their second spring and see if they get rough and chase, and maybe check under the hood then.
:yes:, I see..

often we can figure it out in a second by just touching fish.

Lam Nguyen
11-02-2009, 07:35 PM
Sorry for the late response....some people have to work to make a living.;) Junichi-san, I have not heard or read about thick skin vs thin skin and how this affects their appearance and future growth. Do you think you can elaborate on this? One thing I noticed is that Kiiroogaru has very thick skin and not a lot of luster. How do you think this will affect her appearance and growth?

Lam Nguyen
11-02-2009, 07:37 PM
I told Lam that I bought several Omosakos this year, knowing I would only have the space to keep 2 or 3 into next growing season. So as a curiousity here are the two I'm keeping. The third one shown is listed somewhere in the trader forum, but I'm not opposed to keeping it another year also. I like the patterns, but there are pros and cons to each of them. I think Lam's has the best body for its age. #1 "Tejima" is my favorite but not certified female, #2 is a chagoi personality in a shiro body and I'm going to have a hard time keeping her from becoming a pot-bellied blimp, but very nice shiroji. #3 has excellent height on the body, but head is a little pointy and a lot of black. I basically stuck with these two (or three) because they are the most aggressive eaters, and the first two are now at 18 inches.


Wow Jeff, now I know why you sold the "yellow" koi. The koi that you are keeping look awesome! Good white and good growth. Tejima looks very nice!

Lam Nguyen
11-02-2009, 07:52 PM
:yes:, I see..

often we can figure it out in a second by just touching fish.

Junichi-san, clearly in this "female" game, we as hobbyists have to be able to accurately sex koi (and not take dealers' words for it because they are known to be wrong). From personal communication and literature, I heard that breeders are very accurate at sexing koi. In fact, they can accurately sex koi at 8-10" in length. By the time the koi is 16-18" in length, then it is almost impossible to get the sex wrong. Is this correct?

If I may take this opportunity to refresh on the art of sexing koi, here is what I have learned (and please correct or add any comments you may have):

1. Young koi at tosai and ake nisai - males have pointier pectoral fins and leading rays are thicker. By the spring of their ake nisai (before they turn nisai), some males may have milt and their vents are starting to develop into either male or female vents. The pectoral fins and gill plates may have a fine sandpaper feel.

2. At nisai (end of their 2nd growing summer), the vents should be pretty obvious. Some male koi may not have the rough sandpaper feel yet since they are not sexually mature until ake sansai or sansai.

Going back to your point about "often we can figure it out in a second by just touching fish", are you talking about the fine sandpaper feel on the leading rays of the pectoral fins and the gillplates? Take these Omosako shiro for example, are you saying that at this age (nisai) and size (18") that the males should have a fine sandpaper feel and their vents look like male vents? Also, what about milt production?

The reason why I am asking is because I have a Matsunosuke (or two for that matter) that are about 17" in length and nisai. I thought that they were females, but one has a male-looking vent and I can barely feel the roughness on the two pecs but gillplates are smooth. The other male also has what appears to be a male-looking vent but no roughness at all. In fact, it feels as smooth as Kiiroogaru's and one of my sansai female gosanke. Do you think that these Matsunosuke kohaku's are males? Your opinion is much appreciated.

Lam Nguyen
11-02-2009, 08:02 PM
Three more things, Junichi-san. If a koi produces milt, then it's a definitive male. This means that once a koi produces milt, then it will not resort back to being a female koi in the future. Is this correct? Oftentimes I hear of case samples of male koi turning into female koi in the future or vice versa. I think that this is just a myth that should be put to rest. Koi cannot and do not change sex.

Similar to the milt example, if you can feel a fine sandpaper-like feel on a koi's pectoral fins or gillplates, then is this a definitive indication that it is a male? In other words, are there any examples that you know of where a female koi has sandpaper-like feel on their pectoral fins?

How about koi vents? Vents can be very accurate indicators of whether it is a male or female, right? Are there any examples where a koi with a male vent turns out female or vice versa? I want to know as much as I can about how to sex koi and I thank you in advance for sharing your knowledge and teaching this rook!:D:

Lam Nguyen
11-02-2009, 08:06 PM
One more thing to share. Here is a case-in-point of how accurate breeders are at sexing koi. Now I know that they can be wrong once in a while, but Kiiroogaru came with a certificate. This certificate states that she is a female and was only 12" when sexed. When you look at the pix on the certificate, the pec fins and body shape looks like a male (that's why I was worried). Well, I sexed her yesterday and her gillplates and pec fins are smooth as silk and her vent indicates that she is a female. Now, how in the heck was Omosako able to accurately sex koi at this young of age? I WANT to know, Junichi-san, I WANT to know. Also, if breeders can accurate sex 12" koi, then how in the heck do they get the sex of a 17" koi wrong?!

BillJ
11-02-2009, 08:06 PM
My knowledge is little but from my own experience with a SU that is prone to yellow easily Hi Silk has given me the best results. That's about all I can add. Good luck with her.

Bill

Lam Nguyen
11-02-2009, 08:09 PM
Thank you Bill. That is what I plan on doing with her. She is in with a few other gosanke and they are currently on a staple of 1/3 Hi Silk, 1/3 Saki Hikari Growth, and 1/3 Saki Hikari Color. I also supplement them with watermellon and a daily ration of Izeki Paste Food mixed with Billion Pro, Chiton, and Magic Powder (some sort of a clay product). I have had very good growth result with this combo, so will see how she will respond to this diet. Kiiroogaru is my three year project and I will continue to update all of you on her development. I want to know more about this yellow skin that is prevalent on Omosako shiros.

Super Kindai
11-02-2009, 08:46 PM
Ahhh, Lam-san. those are a lot of questions, beyond my English ability to explain quickly :D:, so pls give me a time.

BillJ
11-02-2009, 09:05 PM
Speaking strictly with the SU in mind,I'd stay as far away from foods that contain ingredients that specifically target color as you can. Hi Silk does a stellar job of doing just that.

Bill

Super Kindai
11-03-2009, 09:11 PM
Sorry for the late response....some people have to work to make a living.;) Junichi-san, I have not heard or read about thick skin vs thin skin and how this affects their appearance and future growth. Do you think you can elaborate on this? One thing I noticed is that Kiiroogaru has very thick skin and not a lot of luster. How do you think this will affect her appearance and growth?

Lam-san, As you know, once a 50cm/20" was a size for GC and a 60cm/24" was a jumbo size. Nowadays, that is a normal Nisai size for gosanke, and in fact there are 50cm-60cm+ Jumbo tosai (ake nisai ) which is not extremely rare any more.:eek1:

In these days, average Gosanke with a certain background (keito) can grow to 70-75cm (28-30"), or at least they have the genetics to grow, which can be considered as a large size ingeneral. and it does not matter if Gosanke have a thick skin or a thin skin. Instead of just a large but "Jumbo" gosanke tends to have a thick skin which makes a fukurin in many cases...:yes:
some breeders & hobbyists guess that a thin skin will not be able to hold an extra large body so it should be a thick skin type for Jumbo fish...:rolleyes:;):D:

Also, these are not a definite but a tendency......
Thin skin type : white skin color almost all the time. shows its beauty in earlier age. won't makes fukurin.
Thick skin type : yellow skin color when young and will turn to white as koi mature (female) by sansai /yonsai. takes longer time to bloom. will males fukurin.

p.s.) Omosako do love yellow ones when their SU are young.:yes: :D:

Super Kindai
11-04-2009, 01:48 AM
Junichi-san, clearly in this "female" game, we as hobbyists have to be able to accurately sex koi (and not take dealers' words for it because they are known to be wrong). From personal communication and literature, I heard that breeders are very accurate at sexing koi. In fact, they can accurately sex koi at 8-10" in length. By the time the koi is 16-18" in length, then it is almost impossible to get the sex wrong. Is this correct?
When new born tosai pull up from mud ponds by Sept, they are most likely 6"+/- in length. we can guesstimate a gender by "smell" of color tone, size, kiwa, vent, and prettiness, etc but these are still a sort of fortune-telling in most cases. When once they grow by 8-10" in a green house of breeder by the end of the year or the early spring of the following year, a breeder can sex, say 90% so that a herd of selected possible female are being grown continuously in a heated pond until late spring. By the time the tosai ( ake nisai) is 14-16" in length as Jumbo tosai at late spring, then yes, it is almost impossible to get the sex wrong, although there are still few that are not 100% certain. but these not 100% certain ones are being eliminated in the preliminaries of nisai tategoi senbetsu so that there is (almost) no chance to be in a mud pond during summer time.

If I may take this opportunity to refresh on the art of sexing koi, here is what I have learned (and please correct or add any comments you may have):

1. Young koi at tosai and ake nisai - males have pointier pectoral fins and leading rays are thicker. By the spring of their ake nisai (before they turn nisai), some males may have milt and their vents are starting to develop into either male or female vents. The pectoral fins and gill plates may have a fine sandpaper feel.
In addition, male tends to have thick pectoral fins and female tends to have thin pectoral fins. also, male' pec fins are wider and female' pec fins are relatively narrow.

2. At nisai (end of their 2nd growing summer), the vents should be pretty obvious. Some male koi may not have the rough sandpaper feel yet since they are not sexually mature until ake sansai or sansai.
It depends on size. as you know, there are many 5-6" imported "bonsai" koi even nisai..... When once they grow to a certain size, say 10-12", male are sexually grow much faster so that you don't need to wait until ake sansai or sansai. In fact, even one year old male can use as for oyagoi.

Going back to your point about "often we can figure it out in a second by just touching fish", are you talking about the fine sandpaper feel on the leading rays of the pectoral fins and the gillplates? Take these Omosako shiro for example, are you saying that at this age (nisai) and size (18") that the males should have a fine sandpaper feel and their vents look like male vents? Also, what about milt production?
Yes, generally speaking, those Omosako SU at nisai age and size 18", you can feel the touch of the sandpaper not only the leading rays of pec fins and the gill plates but also often almost all over the body (lol), and male show its vent shape clearly, milt production as well..... so, there is almost no way to miss, although there are few exception.

The reason why I am asking is because I have a Matsunosuke (or two for that matter) that are about 17" in length and nisai. I thought that they were females, but one has a male-looking vent and I can barely feel the roughness on the two pecs but gillplates are smooth. The other male also has what appears to be a male-looking vent but no roughness at all. In fact, it feels as smooth as Kiiroogaru's and one of my sansai female gosanke. Do you think that these Matsunosuke kohaku's are males? Your opinion is much appreciated.
a male-looking vent shape dominates over the roughness on the pecs and gill plates at this time of the year. the touch of the roughness will increase in spring seasonally.

Lam Nguyen
11-04-2009, 02:36 AM
Junichi-san, I thank you so much for taking your time to share your knowledge. In terms of thick vs thin skin, I would think that koi with thin skin is more preferred, but your explanation really makes sense. IMO, Kiiroogaru has really thick skin and I suspect that she will have very nice fukurin some day. Will see how she looks 3 years down the road. In the mean time, I will do my best to continue to learn so that I can provide the best environment to bring out the best in her.

Regarding koi sex, I find your post very interesting. This means that it's very difficult, unless you get a certified or confirmed female, to get a female ake nisai or younger koi. The reasoning is because the females are kept to grow on and breeders are very good at sexing koi. I will anesthesize a few of my koi, take pixs of their vents and pectoral fins, and post soon to see if we can sex these koi online. Thanks again, Junichi-san.

I am just curious, do you know what Omosako feed their koi? Bill brought up a very good point about staying away from color food for shiros. However, I spoke to a couple of dealers/hobbyists and they said that it doesn't matter what you feed shiros as long as the shiros are of excellent quality. I know that Omosako probably makes their own food. Do you know how their food differs from the gosanke breeders'?

birdman
11-04-2009, 11:29 AM
Very interesting Guys, please keep it going.

Ethan25
11-04-2009, 12:42 PM
To me the head looks twinged to the side.

a tad crooked.

Jeff Speck
11-04-2009, 02:55 PM
Junichi, thank you for your explanations, very interesting post.

Lam, great idea to take vent pics.

Jeff Speck
11-04-2009, 03:13 PM
To me the head looks twinged to the side.

a tad crooked.

Lol, well it may be a male and the head may be sideways, but if you look closely it's actually a fake fish I made from spare packing materials. Not bad, huh? :D:

Ethan25
11-04-2009, 03:15 PM
Lol, well it may be a male and the head may be sideways, but if you look closely it's actually a fake fish I made from spare packing materials. Not bad, huh? :D:

wow, gotta show me how that is done!

;)

Super Kindai
11-04-2009, 10:49 PM
Junichi-san, I thank you so much for taking your time to share your knowledge. In terms of thick vs thin skin, I would think that koi with thin skin is more preferred, but your explanation really makes sense. IMO, Kiiroogaru has really thick skin and I suspect that she will have very nice fukurin some day. Will see how she looks 3 years down the road. In the mean time, I will do my best to continue to learn so that I can provide the best environment to bring out the best in her.

Regarding koi sex, I find your post very interesting. This means that it's very difficult, unless you get a certified or confirmed female, to get a female ake nisai or younger koi. The reasoning is because the females are kept to grow on and breeders are very good at sexing koi. I will anesthesize a few of my koi, take pixs of their vents and pectoral fins, and post soon to see if we can sex these koi online. Thanks again, Junichi-san.

I am just curious, do you know what Omosako feed their koi? Bill brought up a very good point about staying away from color food for shiros. However, I spoke to a couple of dealers/hobbyists and they said that it doesn't matter what you feed shiros as long as the shiros are of excellent quality. I know that Omosako probably makes their own food. Do you know how their food differs from the gosanke breeders'?


Lam-san, How many koi do we have in our pond(s) and how many koi do we usually see/touch/play at other places like dealers, friends, shows etc in a year? a breeder on the other hand if he breeds 10 pairs for instance, he will see about 2,000,000 - 5,000,000 fry carefully, and then more or less 20,000 tosai eventually within just a half year LOL. we as ordinary hobbyists can not compared with well-trained keen eyes of the pro.:D:

I have never asked what Omosako feed their SU....that's interesting. One thing for sure is that they don't need color food for the SU which is relatively economical.
In conclusion, it does not matter to feed color food to SU's skin condition during growing season unless you feed only color food throughout the year .... because heavily feeding koi in growing season are not pretty as koi in autumn/early winter season anyway. young SU in mud ponds during summer are yellowish without solid sumi on surface as if a white radish.:eek1:

Beside, we don't know why but there is an interesting practical theory by hobbyists that sumi become more darker by feeding color food.:cool3: there are many things that we don't know about a mechanism of sumi, although a research laboratory of the ministry of agriculture, forestry and fisheries in Niigata has been studying about nishikigoi.

Super Kindai
11-05-2009, 02:18 AM
Three more things, Junichi-san. If a koi produces milt, then it's a definitive male. This means that once a koi produces milt, then it will not resort back to being a female koi in the future. Is this correct? Oftentimes I hear of case samples of male koi turning into female koi in the future or vice versa. I think that this is just a myth that should be put to rest. Koi cannot and do not change sex.
Well, if a koi produces milt, then it's a definitive male at that time but male koi turning into female koi is an open fact. Believe it or not, the technique of a sex change has developed in the food industry of edible Magoi in Japan. and a sex change happens in the natural world which is caused by Endocrine disruptor http://en.wikipedia.org/wiki/Endocrine_disruptor / Estrogen http://en.wikipedia.org/wiki/Estrogen

Similar to the milt example, if you can feel a fine sandpaper-like feel on a koi's pectoral fins or gillplates, then is this a definitive indication that it is a male? In other words, are there any examples that you know of where a female koi has sandpaper-like feel on their pectoral fins?
Well, yes in a general situation but I was surprised when I touched my female oyagoi after she spawn because she had "Zara", which is called in Japanese, = sandpaper-like roughness feel on all over her body.: :eek1:

How about koi vents? Vents can be very accurate indicators of whether it is a male or female, right? Are there any examples where a koi with a male vent turns out female or vice versa? I want to know as much as I can about how to sex koi and I thank you in advance for sharing your knowledge and teaching this rook!:D:
Well, yes in general again. I have never heard that a koi with a male vent turns out female shape vent or vice versa, but once I experienced strange thing about vent shape of 30 nisai Omosako SU at a local dealer with my friend. one of local dealer got about 30 pcs of only 4-5" small tosai from Omosako and then the fish were placed into a selling area but could not sell because the price was set too high for the size. eventually the dealer removed the SU tosai to a growing pond of his store back yard in an employee only area.

Several months later, we pull up all the SU from the pond which was totally green water in late summer. It was easy to feel "Zara" but the vent shape of almost all the fish had a female shape !!? No way....this can't be happened?? :confused: :eek1: :no:
...........we could not believe our eyes.:D:

birdman
11-05-2009, 07:04 AM
The vent shape is interesting. You can sex newly hatched chicks or pigeons from the vent shape.

Super Kindai
11-05-2009, 12:17 PM
Junichi, thank you for your explanations, very interesting post.

Lam, great idea to take vent pics.
Omosako Nisai. 18-19"+, Female guaranteed....:D:

:yahoo:

farne230
11-05-2009, 01:12 PM
Junichi-san, are these omosako nisai SU for sale?:eek1:
Bob

Super Kindai
11-05-2009, 01:47 PM
Junichi-san, are these omosako nisai SU for sale?:eek1:
Bob
Yes, it was, Bob-san. a few my friends (in Japan) bought a few of them at the past Spring.

mystery.koi.expert
12-14-2009, 10:10 PM
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
12-15-2009, 05:39 AM
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
12-15-2009, 01:27 PM
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
12-15-2009, 01:31 PM
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
12-15-2009, 01:45 PM
:yes:


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/article.cfm/many_fish_change_sex

APOLONASGR36
12-15-2009, 04:38 PM
Anybody has those vent pictures? I would like to know what the male / female shape is supposed to look like.

CHICHI
12-15-2009, 04:47 PM
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
12-15-2009, 06:38 PM
OK Chichi- so one of those is a male....... :) I can sex snakes- fish are still a problem:) JayInOz

CHICHI
12-15-2009, 06:41 PM
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 :yes: just for Fun the way the Thread transpired over here :yes:

Jeff Speck
12-15-2009, 06:42 PM
first is male, second female

CHICHI
12-15-2009, 06:49 PM
first is male, second female

http://www.koiquest.co.uk/forum/viewtopic.php?f=2&t=7648&hilit=male+or+female :D: ;)

APOLONASGR36
12-15-2009, 07:34 PM
Thanks Chichi!! :punk1:

JayInOz
12-16-2009, 06:25 AM
Thanks Chichi. That Pommie site looks interesting! :) JayInOz

CHICHI
12-16-2009, 07:07 AM
Thanks Chichi. That Pommie site looks interesting! :) JayInOz


It Is :yes: ;)