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  • Another type of black pigmentation?

    About two months ago I posted information on

    http://www.koi-bito.com/forum/main-f...nted-fish.html

    Since that time I described two traits (red eyes and black pigmentation of body) at the same time the outcome was somewhat too complex. Therefore, this time I would like not to touch red eyes (as much as possible) and present in this post data on black pigmentation only, and also to provide some illustrative pictures.

    So, initially we crossed Akame Kigoi male with Kohaku female. 50% of fish in resulting progeny (F1) had normal black eyes and 50% had red eyes. In this post I present data on fish of two progenies obtained by crossing black-eyed fish from F1 (black-eyed x black-eyed). All fish in F1 had white background color and some had pale orange (yellowish) patches; no fish in F1 had any black pigmentation on body. In pictures Male 1 and Female 1 you can see, as an example, two fish used in these two crosses (one female x one male).

    During raising of the obtained progenies we observed that at age of fish approximately 1.5 months some fish acquired black pigmentation on body, typically the first sign was appearance of black stripe in the middle of back before dorsal fin. During the time, the proportion of fish with black pigmentation in these two progenies increased and reached 63 and 71% in two progenies (all fish in these progenies had black eyes, the same as their parents). All other attached pictures are of 5-month-old juveniles from these two progenies (individual photos of fish and group photos of pigmented and unpigmented fish from one progeny). You can see that some fish developed more black pigmentation on bodies but many still had these black predorsal stripes or simply some black spots. Many pigmented fish have some muddy not-attractive appearance.

    Before I investigated inheritance and development of Bekko and Utsuri types of black pigmentation in koi. Based on several signs in this case there is another type of black pigmentation. First, Bekko pigmentation appears at age of fry about 10-14 days while hatched Utsuri larvae are already pigmented. In this case, pigmentation started to develop later (about at 1.5 month age) and specifically (appearance of predorsal stripe). And, what is very important - in this case fish with black pigmentation originated from fish parents without black pigmentation; this is not typical for both Bekko and Utsuri. Appearance of Bekko is controlled by dominant mutation; theoretically it is not possible at all (practically only if small black spots on bodies of parents are not noticed). Inheritance of Utsuri is unknown yet but I do not know cases when this pigmentation resulted from both parents not having this trait. As I noticed above, F1 progeny was obtained by cross Akame Kigoi male with Kohaku female. My suggestion is that genotype of Akame Kigoi male used in this cross contained some recessive mutations for black pigmentation. These mutations were not expressed in fish from F1 progeny but caused the appearance of black pigmentation in fish in the next generation, in progenies obtained by crossing fish from F1.

    I would like to ask KB users? Is this type of black pigmentation in koi known and described? How often it is observed? Does it have some name? Is appearance of predorsal black stripe is typical for its development? Apparently people do not raise many fish with such pigmentation and cull most of them at early stages.

    BorG
    Attached Files
  • #2

    Boris, we appreciate you posting this here, I am not sure we have many comments that are relevant. I would observe, for what it is worth, that Kohaku get shimis, and where that black comes from is a question. Rob

    Comment

    • #3

      Originally posted by RobF View Post
      Boris, we appreciate you posting this here, I am not sure we have many comments that are relevant. I would observe, for what it is worth, that Kohaku get shimis, and where that black comes from is a question.
      Rob
      I always thought that Kohaku shimi came from the same place Sanke sumi came from.

      Comment

      • #4

        Originally posted by BorG View Post
        Since that time I described two traits (red eyes and black pigmentation of body) at the same time the outcome was somewhat too complex and confusing. Therefore, this time I would like not to touch red eyes (as much as possible) and present in this post data on black pigmentation only, and also to provide some illustrative pictures.

        So, initially we crossed Akame Kigoi male with Kohaku female. 50% of fish in resulting progeny (F1) had normal black eyes and 50% had red eyes. In this post I present data on fish of two progenies obtained by crossing black-eyed fish from F1 (black-eyed x black-eyed). All fish in F1 had white background color and some had pale orange (yellowish) patches; no fish in F1 had any black pigmentation on body. In pictures Male 1 and Female 1 you can see, as an example, two fish used in these two crosses (one female x one male).

        During raising of the obtained progenies we observed that at age of fish approximately 1.5 months some fish acquired black pigmentation on body, typically the first sign was appearance of black stripe in the middle of back before dorsal fin. During the time, the proportion of fish with black pigmentation in these two progenies increased and reached 63 and 71% in two progenies (all fish in these progenies had black eyes, the same as their parents). All other attached pictures are of 5-month-old juveniles from these two progenies (individual photos of fish and group photos of pigmented and unpigmented fish from one progeny). You can see that some fish developed more black pigmentation on bodies but many still had these black predorsal stripes or simply some black spots. Many pigmented fish have some muddy not-attractive appearance.

        Before I investigated inheritance and development of Bekko and Utsuri types of black pigmentation in koi. Based on several signs in this case there is another type of black pigmentation. First, Bekko pigmentation appears at age of fry about 10-14 days while hatched Utsuri larvae are already pigmented. In this case, pigmentation started to develop later (about at 1.5 month age) and specifically (appearance of predorsal stripe). And, what is very important - in this case fish with black pigmentation originated from fish parents without black pigmentation; this is not typical for both Bekko and Utsuri. Appearance of Bekko is controlled by dominant mutation; theoretically it is not possible at all (practically only if small black spots on bodies of parents are not noticed). Inheritance of Utsuri is unknown yet but I do not know cases when this pigmentation resulted from both parents not having this trait. As I noticed above, F1 progeny was obtained by cross Akame Kigoi male with Kohaku female. My suggestion is that genotype of Akame Kigoi male used in this cross contained some recessive mutations for black pigmentation. These mutations were not expressed in fish from F1 progeny but caused the appearance of black pigmentation in fish in the next generation, in progenies obtained by crossing fish from F1.

        I would like to ask KB users? Is this type of black pigmentation in koi known and described? How often it is observed? Does it have some name? Is appearance of predorsal black stripe is typical for its development? Apparently people do not raise many fish with such pigmentation and cull most of them at early stages.

        BorG
        I can subscribe to that theory....
        Tim

        Comment

        • #5

          I think we need a breeder to give input on what they observe in their gazillions of fry at first culling. I have reached out to a couple, but I know they tend to be reluctant to post for lots of reasons.

          Comment

          • #6

            Originally posted by RobF View Post
            Boris, we appreciate you posting this here, I am not sure we have many comments that are relevant. I would observe, for what it is worth, that Kohaku get shimis, and where that black comes from is a question. Rob
            Rob, in my opinion shimis are some somatic changes, as moles in humans. But in this case there is type of pigmentation which has hereditary nature.

            Comment

            • #7

              Originally posted by MikeM View Post
              I think we need a breeder to give input on what they observe in their gazillions of fry at first culling. I have reached out to a couple, but I know they tend to be reluctant to post for lots of reasons.
              Exactly what I thought. Only breeders can see this type of pigmentation but not consumers (it exists only in underwater part of iceberg).

              Comment

              • #8

                Originally posted by BorG View Post
                Exactly what I thought. Only breeders can see this type of pigmentation but not consumers (it exists only in underwater part of iceberg).
                I have breed koi every year for about 30 years. The pigmentation you see only appears in koi that have black pigmentation from day 1. But it is only observable for a short time and is usually gone by the end of the first year (often earlier).

                It is more prevalent in Asagi & Shusui

                Comment

                • #9

                  Originally posted by mrbradleybradley View Post
                  I have breed koi every year for about 30 years. The pigmentation you see only appears in koi that have black pigmentation from day 1. But it is only observable for a short time and is usually gone by the end of the first year (often earlier).

                  It is more prevalent in Asagi & Shusui
                  Thanks for sharing. It seems that you described some other type of pigmentation. In my case pigmentation appeared much later and I doubt that it will disappear (although I will trace it in fish of older ages).

                  Comment

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