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Koijazz
07-08-2009, 12:54 AM
I was curious as to which was dominant, long or standard fin?
Are metalic or "plain" scales dominant?
Just curious how the genetics work if anyone knows.

Cwazy
07-08-2009, 03:28 AM
This is a very good question, as that I would like to figure this out as well. I do know that longfin koi were the offspring of crossing ornamental koi with the origional food carp fish in order to produce more disease resiliant koi. This is why longfin's are usually more hardy than the standard fin.

Lets get into a little genetics here and look at punnet squares
Say the food carp is Homozygeous dominant and/or heterozygeous while the ornamental koi is homozygeous recessive. This would make sense in that after crossing a bunch of hetero food carp, you'll get a couple koi.

Now we look into crossing a koi with a food carp in order to produce a longfin. This is where it can get tricky. When crossing, koi are going to be all homo recessive. The carp can be homo dominant or hetero. Now in this cross, I'm going to guess the homo dominant fish are going to be carp, the hetero will be longfin koi and the homo recessive will be standard fin koi.

lol okay and now for where the question comes in. If we cross a standard fin koi (homo recessive) with a longfin (hetero), the odds are 50/50..

Now this is my little hunch of genetics of koi. Anyone want to fill in? I'm just going by simple punnet square evolution.

tyco4357
07-08-2009, 09:49 AM
That was Cwazy, good!

Koijazz
07-08-2009, 09:52 AM
What about the metalic scales verses regular?

Cwazy
07-09-2009, 02:54 AM
Not a clue on how those evolved through so I cant help ya there.

Cwazy
07-09-2009, 03:41 AM
After some reading because I am bored and genetics facinates me...

Doitsu koi comes from crossing a japanese scaled koi with a german, black carp, which has no scales.

As for the ratio, still no idea. lol. Just thought you might want some background history on where they came form.

Koijazz
07-09-2009, 03:05 PM
Thank you for all the replies. I was curious because the next time I breed my koi, I'm g about breeding my plain scaled standard finned female with a plain scaled long finned male and a metalic scaled standard fin male and was curious about the outcome.

saltiery
07-09-2009, 11:29 PM
doitsu IS a german carp. I was bred as a food fish where the lack of scales meant ease of preparation. The Japanese liked this carp and requested some to add to their lines. When you cross wagoi (scaled) koi with Doitsu (scaleless) koi, the result is mirror scales, armor scales and a real mess depending on how many times they're mixed. A doitsu should not have ANY scales except the leather zipper down the back. A few lateral line scales are generally accepted.

tdmeckle
07-25-2009, 09:30 PM
This is a very good question, as that I would like to figure this out as well. I do know that longfin koi were the offspring of crossing ornamental koi with the origional food carp fish in order to produce more disease resiliant koi. This is why longfin's are usually more hardy than the standard fin.

Lets get into a little genetics here and look at punnet squares
Say the food carp is Homozygeous dominant and/or heterozygeous while the ornamental koi is homozygeous recessive. This would make sense in that after crossing a bunch of hetero food carp, you'll get a couple koi.

Now we look into crossing a koi with a food carp in order to produce a longfin. This is where it can get tricky. When crossing, koi are going to be all homo recessive. The carp can be homo dominant or hetero. Now in this cross, I'm going to guess the homo dominant fish are going to be carp, the hetero will be longfin koi and the homo recessive will be standard fin koi.

lol okay and now for where the question comes in. If we cross a standard fin koi (homo recessive) with a longfin (hetero), the odds are 50/50..

Now this is my little hunch of genetics of koi. Anyone want to fill in? I'm just going by simple punnet square evolution.

Are Long fins the result of dominance at a single locus? Most size based things in humans like height are referred to as quantitative traits because many loci are involved in the creation of that attribute. Iím not an expert on this and could be completely wrong but it seems that it might be a little beyond punnet squares. I believe this is why we have to have in-between-ers. Ie standard fin size fish with pom pom nostrils, which I believe is classified as long fin. Maybe the experts can correct me.

Hirogoi
07-28-2009, 06:04 PM
I tried to figure mine out once, but the numbers just never worked. I gave up and just decided to be content with them being pretty. You might ask Junichi.

tdmeckle
07-30-2009, 01:43 PM
This should be really interesting to follow their development.
You've already mentioned that some of the fry are standard fin instead of Longfin, but you netted the pond to have a controlled spawn so you KNOW who the parents are.
Since Longfins are a hybrid of Koi and Indonesian Carp you should see 4 different type of bodies/fins.
1. Obviously you would expect to see longfins just like the parents.

2. You should also see some standard fin Koi, as there is roughly 1 chance in 4 that the "koi" genetics from each parent will be passed on to any embryo.

3. You may also see some shorter Lonfins whose fins are more of a "fan" shape than long and feathery.

4. You also have a 1 in 4 chance of seeing some with longer fins than the parents because of the strictly Indonesian genetics being passed on.

From the latest photo's it appears you do have that kind of mix among the fry, so now the fun begins.
Will there be a difference in the way the various fin types develop in terms of color, body shape, etc...? I think it'll be fun to observe how they come along.

So I found the above quote from " papabear " in the amature breeders forum in a discussion on breeding platinum ogons. I still doubt it is this simple but I'm unsure. I know at one time I read about a university that uses koi as a basis for genetic study so maybe there is some kind of more scientific knowledge on this subject. I still think these are quatitiative traits and that you might get roughly four major types of finnage but probably not four types from a genetic perspective. Multiple alleles interacting could result in a entire array of possibilities that will range from really long fins with long fin characterstics to longer fins without some long fin characteristics to shorter fins ith some long longfin characteristics to standard short fints with standard fin characteristics...just my two cents