Shusui Breeding 2025

[Coldspringsfarm]

Starting a new thread because I now have 2 spawns and it's probably best to keep them in separate threads. So a quick recap, I have a group of parent Shusui that decided to spawn before I was ready due to my own negligence in removing the female. Despite the poor timing, I was able to remove the parents and ended up with easily 1000+ fry. Those fry are still in the 250 gal tank they hatched in and doing well. I started them on a mix of egg yolk and aquamax fry powder and after 3 or 4 days I transitioned to only using the fry powder after realizing the egg yolk really was not high enough protein. The first week+ was a bit slow growth wise, probably due to a cold spell where water temps averaged about 62 degrees. There were some deaths for several days, maybe 5-10 per day. Most that I inspected either had deformities or had no food in their stomach for whatever reason. Now that water temps are back up to 70+ the growth has picked up. I started prepping a mud pond and once the water looks right I will probably move about half of them over. I am reluctant to move all of them and have catastrophe happen. Maybe if they do well I will eventually move them all. Including some pics for reference.
Draining and removing creepy crawly koi eaters:


Filled back up with gravity feed from larger pond. Limed and Fertilized with composted manure. Solar aeration.


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[Matt24]

... Despite the poor timing, I was able to remove the parents and ended up with easily 1000+ fry. ...

Okay, so I gather the fry are shusui/shusui (not shusui/everybody). That's good. Got any pictures of the parents?

... I started prepping a mud pond and once the water looks right I will probably move about half of them over. I am reluctant to move all of them and have catastrophe happen. Maybe if they do well I will eventually move them all. ...

I can see that, being cautious. For when the fry get bigger, do you have a plan to protect against herons eating them?

[spkennyva]

I agree with Matt about some form of protection. Given the setting, you could have a lot of critters looking for a free meal.

[Coldspringsfarm]

Okay, so I gather the fry are shusui/shusui (not shusui/everybody). That's good. Got any pictures of the parents?



I can see that, being cautious. For when the fry get bigger, do you have a plan to protect against herons eating them?

Yes, all Shusui. This is a video from shortly after the spawn. The female is the one that lingers in the corner the longest and the other two are males. My plan was to only use the lighter color male but it did not work out that way. The darker male unfortunately seems to be the more aggressive breeder and the lighter one is mostly interested in eating eggs from what I saw. None of them are jaw dropping specimens but it's what I had available. As far as the mud pond protection, was thinking something like a PVC hoop house type structure with either netting or 50 lb mono to form a cage.
https://youtube.com/shorts/Xoaq8JfgH...9Ym7kJ_egJ5RI0

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[Orlando]

From that youtu.be video am taking a long shot here but am I looking at 12 to 14" fish here, what are the ages of these koi and please don't misunderstand my question because we have a good amount of information to share with you.

[Matt24]

... My plan was to only use the lighter color male but it did not work out that way. The darker male unfortunately seems to be the more aggressive breeder and the lighter one is mostly interested in eating eggs ...

Well who knows? Maybe that darker male will turn out to be a better match for that female after all. They seem to both have quite a bit of orange.

As far as the mud pond protection, was thinking something like a PVC hoop house type structure with either netting or 50 lb mono to form a cage.

Sounds like no freebies for the herons.

[Coldspringsfarm]

From that youtu.be video am taking a long shot here but am I looking at 12 to 14" fish here, what are the ages of these koi and please don't misunderstand my question because we have a good amount of information to share with you.

Not sure what there is to misunderstand. They are 10-12 inches. I am guessing not more than 2-3 yrs old. I bought them in Feb 2024 as 6-7" fish but no info on their age. They actually attempted to spawn last spring but I think the males were not sexually mature as none of the eggs were fertilized.

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[Orlando]

Just my thoughts here, I believe these fish are still in development stages I use to believe that 3yrs old were ok for breeding purposes but time has shown me that females should be atleast 5yrs old they produce stronger and more sturdy fry just my thoughts. Not saying they won't breed.

[Coldspringsfarm]

Just my thoughts here, I believe these fish are still in development stages I use to believe that 3yrs old were ok for breeding purposes but time has shown me that females should be atleast 5yrs old they produce stronger and more sturdy fry just my thoughts. Not saying they won't breed.

I could see that being a factor in fry viability. I noticed a big difference in the egg size between my 10" Shusui and and 14" Kohaku. Presumably a bigger egg translates into bigger fry at hatch. The other benefit of age is you get a clearer picture of the traits of the parent stock. My female Shusui is unfortunately changing for the worse with age. The nice zipper is becoming less uniform. The trouble for me has been the cost of 4-5 yr old quality parent stock. Sort of forced me to buy small and be patient.

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[Matt24]

... I noticed a big difference in the egg size between my 10" Shusui and and 14" Kohaku. Presumably a bigger egg translates into bigger fry at hatch. The other benefit of age is you get a clearer picture of the traits of the parent stock.

All true.

... The trouble for me has been the cost of 4-5 yr old quality parent stock. Sort of forced me to buy small and be patient.

And there's a lot of valuable experience to be gained in the mean time, techniques for improving fertilization rate, survival of fry, selection, and the list goes on. So when they do get to 4-5 years and lay a lot more, bigger eggs, you'll have a better chance of getting the most out of the spawn.

[Coldspringsfarm]

Netted up a few fry to get better footage. We are at about 15 days post hatch. I think growth has been a bit slow due to about 8 days of water temps between 58-62 degrees. The last 3-4 days of warmth has really sped up development. They have had a slight yellow color for awhile, but looks like some darker tones near the tail on a few of these. Finding culling/selection info on Shusui fry is very difficult. The only thing I have found is that a dark spot should form on the heads. Not clear on if that is for both Shusui and Asagi, but I wouldn't mind a few Asagi if they show up.

https://youtube.com/shorts/in3pHQWwm...lfbs5yFsy4HYEj

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[Orlando]

Netted up a few fry to get better footage. We are at about 15 days post hatch. I think growth has been a bit slow due to about 8 days of water temps between 58-62 degrees. The last 3-4 days of warmth has really sped up development. They have had a slight yellow color for awhile, but looks like some darker tones near the tail on a few of these. Finding culling/selection info on Shusui fry is very difficult. The only thing I have found is that a dark spot should form on the heads. Not clear on if that is for both Shusui and Asagi, but I wouldn't mind a few Asagi if they show up.

https://youtube.com/shorts/in3pHQWwm...lfbs5yFsy4HYEj

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Asagi and Shusui run in the same gene pool, most would say Shusui is is a doitsu Asagi. That black mark on the head is called chobo sumi (black) it appears also on Goshiki. As far as culling wouldn't worry about it yet unless you see some with an croocked back wait till they hit that 1.5" at that point pretty much all deformities should be visible. Not sure if you know this about our water in the USA is pretty much hard water a few areas have less alkaline with softer water but the vast majority has hard water and that tends to be the down fall of most Asagi and Shusui with time they darken up.

[Coldspringsfarm]

Asagi and Shusui run in the same gene pool, most would say Shusui is is a doitsu Asagi. That black mark on the head is called chobo sumi (black) it appears also on Goshiki. As far as culling wouldn't worry about it yet unless you see some with an croocked back wait till they hit that 1.5" at that point pretty much all deformities should be visible. Not sure if you know this about our water in the USA is pretty much hard water a few areas have less alkaline with softer water but the vast majority has hard water and that tends to be the down fall of most Asagi and Shusui with time they darken up.

My well water definitely falls on the hard side, but a mud pond in my soils will tend to be very low KH. Lime is almost a necessity. I hadn't thought about hard water affecting Shusui darkness, but have seen it mentioned that some Japanese breeders use concrete ponds to increase sumi.

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[Matt24]

... I wouldn't mind a few Asagi if they show up.

Back in the 1960's, there was a Soviet research project on carp scales describing whether a carp (koi in this case) will be fully scaled, scattered scaled, Doitsu leather (no scales on the sides), or Doitsu linear (row of scales down the lateral line) depending on two gene pairs of each of the parent koi. I have not seen any follow up research by anyone confirming, disagreeing with, or updating these research findings. But my limited experiences have tended to agree with the findings for the most part.

One key is, do either the female or the male or both have a row of scales down the lateral lines (or perhaps a partial row)? Your video of the parents was a bit small, but it looks like the female is leather (no scales on the sides). The darker male is further away when he turns to the side. Difficult to tell, but I think he may be leather also. Is that right? In theory, a spawning between two leather parents cannot produce any fully scaled fry, which asagi are.

[Coldspringsfarm]

Back in the 1960's, there was a Soviet research project on carp scales describing whether a carp (koi in this case) will be fully scaled, scattered scaled, Doitsu leather (no scales on the sides), or Doitsu linear (row of scales down the lateral line) depending on two gene pairs of each of the parent koi. I have not seen any follow up research by anyone confirming, disagreeing with, or updating these research findings. But my limited experiences have tended to agree with the findings for the most part.

One key is, do either the female or the male or both have a row of scales down the lateral lines (or perhaps a partial row)? Your video of the parents was a bit small, but it looks like the female is leather (no scales on the sides). The darker male is further away when he turns to the side. Difficult to tell, but I think he may be leather also. Is that right? In theory, a spawning between two leather parents cannot produce any fully scaled fry, which asagi are.

I think the lighter colored "male" is the only one that I believe has no scales on the side. He has the cleanest zipper scale pattern up top. Both of the others have some sporadic scales on their sides. I read a very detailed paper on koi genetics, possibly the one you referred to, that showed percentages of scale type based on scale type of the parents. Who knows what I will end up with....but I guess that is part of the appeal of breeding!

Edit: This is the paper I saw:
https://www.researchgate.net/publica...n_and_Genetics

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[Matt24]

...Both of the others have some sporadic scales on their sides. ...

https://www.researchgate.net/publica...n_and_Genetics

Thanks for the link to that study. Looks like some good reading material there. I searched it for scalation information and saw that Table 2 (page 24) seem to match up with the study I mentioned.

I have done multiple spawns with two leather males and a female that had a partial linear row on each side. https://www.koiphen.com/forums/showt...u-Kujaku-spawn . I got substantial numbers of all scale types as shown in the bottom row of combination #9 in that table. We know the males had to be ssNn. So the female must be SsNn linear even though the row of lateral scales is not complete. I think she could have been SSNn just based on appearance, but she would have only produced fully scaled and linear fry.

You mentioned that yours have "sporadic scales on their sides". One key is whether those scales are all along the lateral line (probably still linear genetics), or if they look random, some high, some low (scattered scale genetics). Probably linear, since most breeders don't raise the scattered scaled fry.

Kirpichnikov, who is referenced, is the author of the study that I mentioned, which is at
https://www.fao.org/4/b3310e/b3310e14.htm
I was thinking it was written in the 1960's because none of the references at the end were newer than 1968. But it may have been written later since the link in your note mentioned papers by that author from 1981 and 1999.

[Coldspringsfarm]

Thanks for the link to that study. Looks like some good reading material there. I searched it for scalation information and saw that Table 2 (page 24) seem to match up with the study I mentioned.

I have done multiple spawns with two leather males and a female that had a partial linear row on each side. https://www.koiphen.com/forums/showt...u-Kujaku-spawn . I got substantial numbers of all scale types as shown in the bottom row of combination #9 in that table. We know the males had to be ssNn. So the female must be SsNn linear even though the row of lateral scales is not complete. I think she could have been SSNn just based on appearance, but she would have only produced fully scaled and linear fry.

You mentioned that yours have "sporadic scales on their sides". One key is whether those scales are all along the lateral line (probably still linear genetics), or if they look random, some high, some low (scattered scale genetics). Probably linear, since most breeders don't raise the scattered scaled fry.

Kirpichnikov, who is referenced, is the author of the study that I mentioned, which is at
https://www.fao.org/4/b3310e/b3310e14.htm
I was thinking it was written in the 1960's because none of the references at the end were newer than 1968. But it may have been written later since the link in your note mentioned papers by that author from 1981 and 1999.

I will have to pay more attention next time I catch them...I am really not sure about the scale patterns.

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[Coldspringsfarm]

Today is the day! Going to move at least half of this spawn to the mud pond. I have been trying to be patient with starting an algae bloom but it's not going that great. I may have screwed up with the lime application as I have read that it can bind up phosphorus for a month or so. We also have had a lot of overcast days since the pond filled back up. Yesterday I took some samples with a clear cup and there are lots of micro organisms swimming around, so I think it's still better than the 250 gallon tank. I will try to get some pics/vids of the transfer.

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[Coldspringsfarm]

Pond migration was a success! I used a larger skimmer net to catch several hundred at a time and then used a smaller net to transfer over about 20 at a time. I was able to keep a rough count and pretty quickly got to 500 fry without feeling like I put a dent in the tank population. I ended up moving over about 1000 and wouldn't be surprised if there are 500 still in the tank. I went down several times to check on the fry and they quickly dispersed around the pond margins and seem to be acting normal. No wonder the growth seemed to have paused, 1500 in a 275 gallon tank is a lot! Hoping the warmer water and mud environment will boost their growth in short order. Pics are an attempt to show the fry in the transport bag and some modifications I did to overflow pipe to screen out the fry in overflow situations. I know the water looks a bit stained. It's a combination of rain runoff from lastnights storm and the compost I used to try to trigger an algae bloom. Water parameters are pretty good and starting to seem some algae bloom after today's sunshine.

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[Noahsnana]

Yes, all Shusui. This is a video from shortly after the spawn. The female is the one that lingers in the corner the longest and the other two are males. My plan was to only use the lighter color male but it did not work out that way. The darker male unfortunately seems to be the more aggressive breeder and the lighter one is mostly interested in eating eggs from what I saw. None of them are jaw dropping specimens but it's what I had available. As far as the mud pond protection, was thinking something like a PVC hoop house type structure with either netting or 50 lb mono to form a cage.
https://youtube.com/shorts/Xoaq8JfgH...9Ym7kJ_egJ5RI0

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Nice parents I would love to see updates of the fry