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Thread: Zero nitrates and sumi development

  1. #21
    Oyagoi yerrag's Avatar
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    Quote Originally Posted by dick benbow View Post
    His referral to polishing was a mechanical trapping of fines. the fact he used silica sand was the reason the sumi popped....
    That would be another one on my "to do" list then.

    Nivek, the shiro sumi looks very solid. Can you venture a guess why the beni and the sumi of the tancho faded? My guess after accounting for the lockjaw condition is it stopped eating well and would have become muji if you didn't cull it, if it got that far surviving.

    Am I the only one to think chagoi don't merit equivalence when discussing sumi? The lightness and darkness of chagoi involves more than just the imterplay of melanin, it seems a combination of various pigments is involved that result in varying levels of gray and brown, neutral colors that also vary in lightness/darkness as perceived by our eyes. Chagoi and sumi imho muddies the discussion. Still, I like Nivek's chagoi, the lustrous glimmer in olive wrapped in even fukurin brings out the best in a chagoi. Hope its shoulders develop more, but the head could be larger.

    Brutus, thanks for the kumonryu pics. I can see patterns moving all over the place over time. Yet I don't see how you could make the conclusion that in zero nitrate conditions, its patterns couldn't be more stable. After all, those kumonryu are in a pond in temperate climate, with seasonal vaiations in temp and feeding, and your nitrate levels would vary. That patterns are so much in flux doesn't indicate such behavior can't change under Nivek's zero nitrate conditions. So I would still encourage Nivek to try out a kumonryu in his pond. Nivek, please get a kumonryu

  2. #22
    Honmei Brutuscz's Avatar
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    Maybe it could...but, with kumonryu, conclusions are tough to make. The only thing I concluded was that changes happen pretty randomly. My best results seemed to be the ones with less sumi when they were small. So now..I look for mostly white ones. Definitely a fun variety to own. But, I would not spend much money on one.

  3. #23
    Oyagoi yerrag's Avatar
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    Understandably so. I'm not getting any kumonryu myself because with my limited pond size and with flow being restricted, my filter capability leaves me with no room for a large koi population. So I have to be judicious in choosing which koi to raise, and kumonryu gives me iffy chances of success. One unspectacular goshiki is enough, which can't get a good sumi background, but I'm keeping it even if it's a thin male, just so I can see if its sumi improves when I get my nitrate levels lowered permanently. Keeping my fingers crossed if I can pull off the trick of lowering nitrates.

  4. #24
    Jumbo RobF's Avatar
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    I think Mike is right when he says it comes down to “melanin”. True enough but it is not unlike saying it all comes down to “women”. No amount of study, however rewarding, is likely to produce much influence over either. Here is a science paper about melanin, most of it is way beyond what is of much use to the kichi, but a quick read does reveal some interesting things about melanin. I’ll briefly summarize a few.

    Melanin is the black pigment seen in fish, sumi we call it. Melanin is found in the radial arms of pigment cells called melanophores. The melanin in these arms is contained in many tiny moving structures called melanosomes. Fish appear darker when the cell’s arms fill with many dispersed melanosomes and that same fish can then appear lighter by aggregating the melanosomes, moving them, to the center of the cell. The chemistry of melanin is long established at the gross level, but closer examination indicates poorly understood complexity. Melanin may actually be more than one chemical. 99.9% of absorbed radiation, UV and light, is converted to heat. Melanin is especially absorbing of the highe renergy photons at the UV end. Melanin can be found in the fossil record both for dinosaurs and fish. Melanin has for decades been considered a semi-conductor but it now appears that this model is also inadequate. Research indicates that light skinned people experience 40 times the DNA damage due to UV as do dark skinned people. This seems to be because that in addition to absorbing the offending light melanin also seems to deal with the free radicals that are created. Numerous studies have been done regarding melanin’s affinity to metals, such as copper and cadmium, there does not seem to be any mention of silicon, which is not a metal, in this context. And so on …

    http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0749.2006.00345.x/abstract

  5. #25
    Daihonmei MikeM's Avatar
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    Rob's reference to metals will be confusing to a lot of folks. Silicon is referred to as a metalloid. You can think of it as a pseudo-metal. It almost never appears in pure form in nature, but if you saw a lump of it, it would look like a metal. But, it does not act like a metal, at least most of the time. It is brittle, not malleable. Silicon combines readily with oxygen to form silica (silicon dioxide), and is very common in the form of silicate compunds... in sands, clays and silicate minerals. It is all around us in cement, mortar, concrete, glass, ceramics, porcelain. Although it is not a metal, in certain conditions it can behave like a metal, such as by mixing with some metals to form an alloy. In purified form it gets used in the semiconductor electronics which allow us to have this forum.

    Perhaps the metalloid nature of silicon has a role in why it contributes to enhancing sumi in koi??? ... melanin's affinity for metals that Rob mentions.

    Enough chemistry.

  6. #26
    Oyagoi yerrag's Avatar
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    "Melanin is especially absorbing of the higher energy photons at the UV end."

    Interesting. This would mean it absorbs less and reflects more at the IR end. This means that melanin would be more of a reddish black, which is ungainly. Other pigments, I guess, would then have to be at play to make the sumi much darker looking.

    When I was making printer's ink, I learned this factoid: that blue makes white appear whiter and also makes black appear darker. So we'd add UV brighteners to our varnish to make the paper it's printed on brighter and whiter. It's the same thing Tide adds to detergents to make your clothes brighter and whiter. Next time you look, see if it's the blue tinge that's actually making your clothes whiter. And for that matter, who knows, the shiroji of your koi. For the black, we'd be adding ultramarine blue to carbon black for that black with oomph.

    And then of course, it also helps that the slime coat is healthy and lustrous. It's like your hair dull and flat applied with pomade and suddenly it looks rich and vibrant. The reason is that a lustrous slime coat or a pomade reduces the roughness of the surface, and instead of reflections bouncing all over the place, it is concentrated in your eyes at the angle of incidence.

    It makes more sense now that Utsuri has Asagi lineage, the Asagi must be providing the blue pigment genes.



  7. #27
    Daihonmei MikeM's Avatar
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    "It makes more sense now that Utsuri has Asagi lineage, the Asagi must be providing the blue pigment genes."

    But, Asagi does not have blue pigment. The blue color is an optical illusion of looking at underlying sumi through the skin. It is a dilute sumi, which becomes a soft gray on the surface as the pigments mature. With Shusui the gray tone becomes more definite than in Asagi due to the lack of scales. A similar effect can be seen in some Sanke around the edges of black patches where additional sumi is forming under the surface skin. When sumi forms in the surface layers, the blue effect is missing.

  8. #28
    Oyagoi yerrag's Avatar
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    Quote Originally Posted by MikeM View Post
    "It makes more sense now that Utsuri has Asagi lineage, the Asagi must be providing the blue pigment genes."

    But, Asagi does not have blue pigment. The blue color is an optical illusion of looking at underlying sumi through the skin. It is a dilute sumi, which becomes a soft gray on the surface as the pigments mature. With Shusui the gray tone becomes more definite than in Asagi due to the lack of scales. A similar effect can be seen in some Sanke around the edges of black patches where additional sumi is forming under the surface skin. When sumi forms in the surface layers, the blue effect is missing.
    I'm not convinced there isn't a blue pigment or expression involved Mike. Calling the blue an illusion of black forces us to accept a premise that is suspect. I would agree if the perceived blueness of the asagi is a tint (say 10%) of the bluish-black sumi, which reveals to us the blue component of sumi that otherwise would have been hidden if the sumi were very strong.

    A black where the red region is more reflective than the blue region of the visible wavelength, is a reddish-black. A bluish-black, relative toi a reddish-black, is where the blue region gets to be more reflective. A reddish-black sumi won't be as attractive as a bluish-black.

    But then again, I'm no expert. I'm just telling it like I see it. Who knows? Maybe melanin has different flavors, and maybe there isn't a blue pigment but a blue flavor of melanin, or maybe there really is a blue pigment. We may know ten years from now?

  9. #29
    Oyagoi yerrag's Avatar
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    I don't know what's going on but the server must be having hiccups. I just wrote a long post and it's gone. And it never auto-saved at all.

    So trying again..

    There may not be a blue pigment but the blue in asagi I won't readily ascribe to an optical illusion, It is there and if it is a component of sumi, it's my opinion that it has bearing on the quality of the sumi. A sumi that is reddish in appearance cannot best a sumi that is bluish in appearance. One is washed out and the other jumps out. The difference in contrast to the shiroji can't be emphasized enough.

    Edit: That post got through, I get two posts.

  10. #30
    Jumbo RobF's Avatar
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    The black and the red/orange/yellow seen in koi skin are pigment cells (tiny blobs of paint). White, metallic and gin rin are reflective color cells (tiny mirrors). Blue, green, gray, purple and brown are combinations of pigment and/or reflective cells. The blue in asagi is black overlaid with a reflective layer, the blue light is preferentially reflected by the mirrors and the black layer below absorbs the rest. If you want green put yellow above the mirrors. Koi can do “powder blue”, especially young koi, but have not achieved the “electric blue” seen in other fish since this requires special spacing of the reflective bits. Watching for this arrangement to appear spontaneously, as the koi farmers have done, apparently doesn’twork. Parent selection based on microscopic examination is impractical since the structures are so small as to require electron microscopy. Genetic engineering for the characteristicis uncertain at best.

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