Home | About Us | Contact Us


Koi Forum - Koi-Bito Magazine straight from Japan
Page 2 of 2 FirstFirst 12
Results 11 to 19 of 19
Like Tree12Likes

Thread: A Ramble About Selecting Tosai For Future Size

  1. #11
    Honmei ricshaw's Avatar
    Join Date
    Mar 2010
    Location
    Southern California
    Posts
    2,653
    Quote Originally Posted by RayJordan View Post
    Koi breeders have a completely different agenda than the natural order of things. Breeders cull for elements like body shape, size, and beauty, etc. These are recessive genetic traits rather than the dominate natural path of only let the strong survive. It has been said that if a breeder loses even 20% of their fry before they are culled at various stages of development the very best potential koi will be lost as the best are typically the weakest as babies. Another reason to removed the tobi's as soon and often as possible.
    Is culling the tobi's really culling for "size"?

  2. #12
    Sansai almostgeorgia's Avatar
    Join Date
    Aug 2008
    Location
    Amelia Island, FL
    Posts
    286
    It would stand to reason that breeders would keep the largest and best looking 'jumbo' tosai to grow on for more profitable nisai. But based on what Ray is also saying in his post on culling for Tobi's, above, and that fact that nature often 'staggers' growth rates in the cohort of any given spawning season, doesn't it stand to reason at least some of the tosai sold off at, say 6", may still experience a later 'growth spurt' and achieve good (80bu) if not exceptional size with good husbandry? Put another way, I understand one's best odds, though never a guarantee, to achieve maximum size may rest with a jumbo tosai. But isn't it still possible if not probable at least some of the smaller, more average sized koi at a given age (NOT runts), might still experience some very solid, good growth as nisai and sansai?

    My suspicion this may, indeed, be the case rests with Ray's example that just about all animals, and fish in particular, have varied growth rates in the young of the year, for purely genetic driven survival reasons. An extreme example is the vastly different sizes seen in the new spawns of annual killifish. Because they typically hatch grow, spawn and die all within a one year or annual cycle, 'Tobism' or 'Shooters' are even more magnified and noticeable. But a practiced breeder of these fish doesn't fall to temptation and ONLY keep the Tobi's to spawn the next generation. Many of these super-sized fry grow so fast they literally 'burn out', spawn and die within 6 months, or even less. The more experienced breeder will keep some of his more 'average-sized' fry that will still eventually reach maximum size, and indeed may have even more color and sexual vigor at 10 or 11 months, than their shooting- star siblings, now long dead.

    Perhaps an obligate annual like a killifish is not very analogous to a much longer lived koi. But thousands of generations of Tobi's and 'slower growers' in ancestral koi must have arisen for a reason. Their waters are not as ephemeral as an annual rain pond on the African veldt, but still no less harsh and unpredictable at times, making 'staggered' spawning cohorts a defensive mechanism for continued survival. The Japanese no doubt select the best 'jumbo tosai' for nisai grow out, going with better odds for truly larger fish next season, all based on their long experience. But as they cannot hold over anything but a tiny fraction of their annual spawn, is it not possible that they may indeed, be passing on at least some portion of good potential 'late bloomers' as first year culls?

    Maybe another way to ask the question; is there any evidence an 'average sized' tosai, not a jumbo, ever goes on to become an 85bu All Japan GC?

    Or am I just trying to convince myself that little 6" tosai really DOES have 'Show-Stopper' potential?

  3. #13
    Honmei ricshaw's Avatar
    Join Date
    Mar 2010
    Location
    Southern California
    Posts
    2,653
    Quote Originally Posted by almostgeorgia View Post
    Maybe another way to ask the question; is there any evidence an 'average sized' tosai, not a jumbo, ever goes on to become an 85bu All Japan GC?

    Or am I just trying to convince myself that little 6" tosai really DOES have 'Show-Stopper' potential?
    We are back to "genetics" for growth and selection for positive traits. If you use good jumbo olyagoi and select fry for body and pattern, I would think there is potential.

  4. #14
    Oyagoi RayJordan's Avatar
    Join Date
    Dec 2003
    Location
    San Antonio, Texas
    Posts
    1,780
    There are lots of variables and possibilities with a six inch tosai. Tosai just means they have experienced a single growing season(summer) Depending on when they were spawned they could be a spring, summer or even fall hatch. So if buying a tosai in April for example it could be a year old or it could be only 7-8 months old. It might have been held over the winter in colder water with minimal feeding and growth or it might have been kept in a heated greenhouse and force fed for max growth. It could even be a stunted two year old koi but that is getting off topic.

    Only by knowing or trusting the information we are given about tosai genetics, age, growing conditions, sex, etc. can we begin to guess what might occur as far as potential growth. I do not believe that there is a better chance of "jumbo tosai" that were created in artificial conditions in heated greenhouses and fed for maximum growth to become Champion quality jumbo adult koi vs the koi selected to be grown in a more traditional manner having the same genetic potential.. The best show quality mature koi were grown and developed at a more moderate pace is what I have been told. Yes, there are exceptions with jumbo Champion 4 & 5 year old koi being created using special growing methods. Remember the adage that about peaking too fast!
    Disclosure:These opinions are based on my experience and conversations with persons I consider accomplished koi keepers and do not reflect the viewpoint of any organization.

  5. #15
    Honmei ricshaw's Avatar
    Join Date
    Mar 2010
    Location
    Southern California
    Posts
    2,653
    Quote Originally Posted by RayJordan View Post
    Only by knowing or trusting the information we are given about tosai genetics, age, growing conditions, sex, etc. can we begin to guess what might occur as far as potential growth. I do not believe that there is a better chance of "jumbo tosai" that were created in artificial conditions in heated greenhouses and fed for maximum growth to become Champion quality jumbo adult koi vs the koi selected to be grown in a more traditional manner having the same genetic potential.. The best show quality mature koi were grown and developed at a more moderate pace is what I have been told. Yes, there are exceptions with jumbo Champion 4 & 5 year old koi being created using special growing methods. Remember the adage that about peaking too fast!
    I am not an expert... and don't know the answer... but, if all conditions were equal, would the larger tosai in a spawn have a better chance at reaching jumbo?

    It has been my experience growing tosai that the ones with the greatest appetite at feeding time tend to grow faster and larger than the shy ones.

  6. #16
    Oyagoi RayJordan's Avatar
    Join Date
    Dec 2003
    Location
    San Antonio, Texas
    Posts
    1,780
    It is my understanding that Tobi's are in a sprint to become sexually mature and reproduce. This can happen in the 1st year in warmer climates. Once the hormone cycle kicks in the growth will slow down as energy is channeled to producing eggs or sperm. These early hormonal changes also effect growth and other qualities like color development that we value in a negative way.

  7. #17
    Honmei ricshaw's Avatar
    Join Date
    Mar 2010
    Location
    Southern California
    Posts
    2,653
    Quote Originally Posted by RayJordan View Post
    It is my understanding that Tobi's are in a sprint to become sexually mature and reproduce. This can happen in the 1st year in warmer climates. Once the hormone cycle kicks in the growth will slow down as energy is channeled to producing eggs or sperm. These early hormonal changes also effect growth and other qualities like color development that we value in a negative way.
    Thanks. I did not consider the role of hormonal changes.

  8. #18
    Daihonmei MikeM's Avatar
    Join Date
    Dec 2003
    Location
    Orlando, Florida
    Posts
    11,128
    [QUOTE=almostgeorgia;213918]It would stand to reason that breeders would keep the largest and best looking 'jumbo' tosai to grow on for more profitable nisai. But based on what Ray is also saying in his post on culling for Tobi's, above, and that fact that nature often 'staggers' growth rates in the cohort of any given spawning season, doesn't it stand to reason at least some of the tosai sold off at, say 6", may still experience a later 'growth spurt' and achieve good (80bu) if not exceptional size with good husbandry?

    First, let's not confuse Tobi fry with desirable nishikigoi. Tobi fry are genetic throwbacks, unrefined and plain. The breeder would end up getting rid of them even if not taught by the experience of generations to cull them immediately. Keeping them 'to see what happens' taught that they ate a lot of food, consumed undersized hatchlings and were not worth trying to sell.

    When we talk about koi becoming large, what do we mean? It was a big deal when a gosanke as big as 80cm came along. Look back at the ZNA or Shinkokai All-Japan GCs from 45 years ago. Any pondkeeper can have higher quality and larger koi without busting a budget. Gosanke are so much more refined and larger today. The usual reference point nowadays seems to be 85cm to say a koi is 'jumbo'. Why not 90cm? A full meter? "Big" is relative. My oldest koi is 80cm. It was once my goal to have all my koi be as large as her.... her hugeness was so impressive. Now that there are others larger, she does not seem so big, but she is a size that a person can handle. Much larger and koi become a real challenge to handle. Perhaps the more important question is how large a koi can be comfortably raised in the pond? If they cannot move comfortably, there isn't much to enjoy.

  9. #19
    Oyagoi yerrag's Avatar
    Join Date
    Jul 2013
    Location
    Manila, Philippines
    Posts
    1,792
    Knowing about tobis makes me appreciate more the tosai that I see that are shipped in. With talk about jumbo giving undue weight to size, I could easily get lost and fail to appreciate the inherent potential of a tosai that is a runt, but only a runt relative to its tank mates. It would be a good strategy then to remove the bias towards size and consider each tosai under consideration as equally sized. From this prism of koi appreciation can we make selection of koi more rewarding. Is this something I can take with me each time I go tosai shopping?

Page 2 of 2 FirstFirst 12

Similar Threads

  1. Selecting Tosai Shiro Utsuri
    By MikeM in forum Main Forum
    Replies: 26
    Last Post: 07-14-2013, 07:54 AM
  2. Continuous Filtration System: Size? vs Pond Size
    By KoiKisses in forum Pond Construction
    Replies: 2
    Last Post: 08-23-2009, 05:50 PM
  3. Picking For Future Size ?
    By HEADACHE6 in forum Main Forum
    Replies: 51
    Last Post: 02-24-2008, 11:10 AM
  4. Selecting Tosai, pointers...
    By erwinsan in forum Main Forum
    Replies: 66
    Last Post: 02-12-2006, 08:15 PM
  5. Selecting For Size
    By MikeM in forum Main Forum
    Replies: 5
    Last Post: 08-23-2005, 02:00 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Articles - Sitemap - FAQs and Rules

KB Footer Graphic
Straight from Japan... For the serious hobbyist!
All content and images copyright of: Koi-bito.com