Tuesday, February 7, 2012

Tobi-Koi Fry


Tobi-Koi Fry- Photo By en.wikipedia.org


Tobi

What is tobi defined-Tobi: (Toe-Bee) jump; in koi fry it refers to koi that jump in size by eating their siblings. It is very important to remove these tobi koi when sorting fry from a spawn and placing the tobi in separate aquarium; keep the tobi do not destroy the tobi.

Anyone who breeds koi knows about tobi. In other species these are often called "shooters". Koi fry can and do also occur in goldfish spawns; these are the fry that grow to juvenile size at break neck speed and they are noted for eating their smaller siblings. Most koi breeders assume tobi koi do not have the refined characteristics the breeder is looking for, however this is wives tail most  koi fry do in fact are generically the same as their smaller koi fry siblings.


What Causes Tobie's? The Answer We Don’t Know: but here’s what we do know.
The primary belief all tobies are not worth keeping and must be destroyed this is mistake Tobi is generically the same to their smaller koi fry siblings, so what explains tobi koi versa same spawn smaller fry siblings.

Behavior killing or eating siblings is well documented in the animal world. Life in the wild or breeding environment can be so brutal, sometimes animals are forced to do terrible things to ensure their survival. Cannibalism and infanticide are well known in many species, but perhaps the most disturbing cases are those of baby animals killing their siblings, sometimes moments after they are born or in the uterus of their mother like the sand tiger shark! Here is a list of just a few species that start their lives as ruthless fratricides or cannibals.
  • Praying Mantis
  • Queen Honey Bee
  • Copidomopsis Floridanum Wasp
  • Sand Tiger Shark while still in their mother’s uterus
  • Tobi Koi
  • Hamsters,
  • Rats,
  • Squirrels,
  • Bats,
  • Seals
  • Sea lions,
  • Otters,
  • Polar bears
  • Lions,
  • Tigers,
  • Chimpanzees,
  • Nazca boobies,
  • Black Eagle,
Species, like koi fish, eat their own young. For example, egg-eating is rampant among male and female koi fish breeding or guarding egg nests. Researchers have found that while the nests often contain eggs sired by other dads, the fish aren’t terribly discriminating in the eggs they munch, which means they’re often eating their own koi fry.




It may be worthwhile to the koi fry fish, experts suggest, because the nutrients supplied by the eggs improves their odds of producing viable eggs and offspring in the future, which increases their lifetime reproductive fitness. Alternatively, the practice may perpetuate because it has a “neutral” effect, neither harming nor helping the lifetime reproductive success of the animal. Egg-eating may simply be a behavior that can occasionally come in handy.

Genetics:

Tobi koi and tobi goldfish carry in their genetic code remnants of everything that come before. A top-notch pair of gosanke or ranchu carries all the genetic material needed to make the ancestral common carp or crucian carp from which they were derived through selective breeding. Koi fry also have all the genetic material needed to recreate the incremental steps in their evolution. In the offspring from a pair of sanke you will find kohaku, higoi and perhaps even a magoi. A group of ryukin offspring may include tobi individuals with characteristics of wakin and common goldfish.




The more ancestral forms are always more hardy. Koi left to their own devices and allowed to breed indiscriminately for many generations, a population of koi will revert back to something resembling the ancestral common carp and goldfish will revert back to something resembling a crucian carp. In a group of sibling fry, those with a more latent genetic make-up will be just a little bit stronger and faster giving them a slight advantage when it comes time to eat or avoid a predator.

But, in the world of koi fish fry, a slight advantage can become amplified many fold. There is a snowball effect. A fry that gets just a little bit bigger than its siblings is better able to capture and compete for food so it grows faster; the larger the size disparity, the bigger the advantage. So, over just a few weeks time an tobi individual that is just slightly larger could be to the serendipity effect.



Tobi are larger than their koi fry siblings becomes ten times larger than its siblings. At some point, the size disparity becomes so great that the larger individual can eat its siblings providing it with a new limitless food supply. The a process that starts from an initial state of small insignificance and builds upon itself, becoming larger and perhaps potentially dangerous or disastrous (a vicious circle, a "spiral of decline"), though it might be beneficial instead (a virtuous circle).

Serendipity Effect

How can some tobi be excellent examples of highly refined koi or g goldfish and show no signs of being a latent ancestral form? I think it is because there is the serendipity effect and factors at work as well.

Imagine a group of larvae which have absorbed their yolk sack and are ready to begin feeding. Perhaps some arrive at this stage a few hours ahead of the rest because they were spawned first or their position on the koi fry spawning substrate was a fraction of a degree warmer then the rest, or because of some other factor. The larvae instinctively dart at a moving food particle. Some times they catch it and sometimes they miss.


They are growing extremely rapidly and catching one or two extra choice food morsels can make a difference in that growth rate. Some individuals are just lucky and are able to get a tiny bit ahead of their siblings. As described above, a very small advantage can quickly snowball into a large advantage. An individual with no innate genetic advantage can become a tobi just through serendipity effect.

Other Koi Fry Observations

In some batches of koi fry the size distribution is large and there is an unusually large number of koi fry tobies In other batches the size distribution is narrow and the siblings look almost identical. In general, the better the fry are fed the less variation there will be in their size. If abundant live food can be kept in front of the fry at all times while maintaining good water quality, there is a much lower incidence ofkoi fry tobies.



Under the best of conditions the growth of fry is phenomenal and most of the population (except for those with serious deformities) has the potential to grow at the rate of koi fry. The best way to minimize the number of tobies is to provide better nutrition and husbandry.

The biggest and best koi and goldfish will have had the best nutrition and water quality their entire lives. Periods of less than optimal conditions can have long-term effects. In extreme cases, we say that the fish is stunted.

The younger the koi fish, the more severe and lasting the effect of poor nutrition and water quality. Tobi are considered by most to be undesirables. If they are genetic throw-backs then they probably are undesirable. However, you should be on the look-out for those  koi fry fish which have both the genetic potential to meet your selection criteria and the serendipity factor  to have gotten off to a fast start in life and become a superb genetics or genes.

 


It is always a good idea to separate tobi if you can; especially if they have become large enough to be cannibals. Never automatically assume this koi fry has no potential; you would be wrong; just remember the tobies are bigger, stronger and are generically the same as their baby brothers and sisters.
  

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Friday, February 3, 2012

Sexing Koi, Breeding Koi, Spawning Koi, Raising Koi Eggs and Koi Fry

Sexing koi- Photo By nishikigoi-info.com


Sexing Koi Fish

Females, especially in season are far more rounded than male fish which tend to be slim at all times. The pectoral fins of male fish tend to be larger and more pointed than those of female fish, but this is by no means always the case.

During the breeding season, male fish can display a rough surface to the gill plates, again however, not always. To be sure, net the chosen fish and apply gentle pressure along the lower abdomen wall with your thumb and forefinger towards the vent. Male fish show signs of milt from the vent, whereas females in season will provide eggs! This operation should however be performed with great care so as not to injure the fish. 

I find the only sure way to sex fish is to watch the fish. The ones that lay eggs are female, the ones that chase are the males

Pairing




This is always initially a process of trial and error. Always pair like varieties if you are trying to produce a certain variety. For example, if you are trying to breed kohakus, use kohaku male and female fish. Crossing a kohaku and sanke/showa is acceptable, crossing a kohaku and a Yamabuki for instance will probably produce only ghost and black koi.


Remember that male genes tend to be dominant in any pairing.  Always select adult fish only to ensure successful spawning. Once you have found a pairing that gives some good fish – keep it. If you find a pairing that produces show winners, give me a ring I'll buy them!!


Preparation
Separate males and females at least one month before you intend to spawn the fish.  Provide a reasonably small pond – ideal 2 x 3 x 1 meter deep  Or use a spawning net in your main pond.  Don’t feed the parent fish for a few days before you expect the fish to spawn.

Prepare your growing on pond(s) by seeding them with chicken manure or (if you are worried about your koi catching salmonella!) use leaf mold to encourage the production of infusoria and daphnia which the koi fry will need in abundance from day one.

Spawning





Spawning usually takes place 1 – 3 days after introducing male(s) to the female(s). It can take place at any time of day or night, unfortunately, typically spawning seems to happen around two am (about the same time as most babies are born!).  Spawning can be triggered by temperature changes, change in water conditions, introducing new fish or barometric pressure changes (i.e. thunder.)

Water Conditions

Koi will spawn when the water temperature reaches around 18 Deg +. As always, you need to ensure prime water conditions with zero   ammonia or other pollutants present.  I have found that the addition of Refresh or similar clay products to the water can to get them going ! To achieve and maintain the necessary water temperatures early in the season (late May) it is a good idea to provide heated conditions so that you can achieve a spawning as early as possible to maximize the length of the growing season.

Spawning media

I recommend using purpose made spawning ropes. These are soft and easy to handle.  Don’t use blanket weed – it is too difficult to collect the eggs without damaging them. A good quantity of media is required to collect all the eggs and encourage spawning.



Remove eggs as soon as they are laid to prevent parents eating them. This is obviously easy to do if you have used spawning ropes. Move eggs on ropes to vat or separate tank for hatching. This should contain water of approximately the same temperature as the spawning pond and should be well oxygenated. It does not however need to be filtered. Eggs introduced straight into growing on ponds are vulnerable to predators such as snails, tadpoles and dragon fly larvae etc. Having worked so hard to achieve the spawning in the first place, don't use them as a food source for the local pond wild life!


 

Handling Fry

Once the fry have hatched, after about 4-5 days, depending on temperature you will need to move them to the growing on ponds. Fry can be moved even when a few days old using plastic bags or fine mesh net. Handle with care however since they are easily damaged.


Culling

Now comes the tricky part. To cull fry successfully you must:

  • know the parent stocks;  
  • have extremely good eyesight; 
  • have experience;  
  • and there are a few basic principles that should be followed; 
  • watch out for Tobi they will eat and feast on their smaller siblings;  

    For example, Utsuris and Showas should produce black fry. Whites and reds develop. You should destroy any fry which are not black. With kohaku /Sanke fry will tend to be orange or orange and white. Any pure white or black should be culled.

    If you are breeding patterned fish you should generally speaking destroy all plain colored fry.   I find that the fry need to be at least 6-8 weeks old before I can see what I am doing!  The Japanese breeders start culling generally at 4 weeks.

    As the fish get larger, cull out any with deformities, missing fins, two heads etc.  Ideally you should cull several times in the season, but in practical terms I find that Herons and Kingfishers do more culling than I do!.  Culling is clearly important to reduce numbers to ensure that the fish that you want reach a reasonable size by the end of the season.


    Feeding

    The fry need an ample supply of live, natural food if they are to survive and grow quickly. Providing the proper growing on pond environment is the surest way to provide a good supply of daphnia and infusoria, on which the fry will develop. Whilst tempting. no dry or artificial food should be given to fry for at least six to eight weeks – it can damage the gills and is also likely to pollute the growing on pond. Any slight build up of ammonia or nitrite will kill fry very quickly indeed.

    Growing 

    Fry normally reach between 2 and 4 inches by mid October assuming spawning in early June. Factors which will affect growth rates are: - temperature, food supply, volume of fish and variety. If you don't cull, you may end up with a lot more babies, but they will be very much smaller than desired. Also of course, your food source will be depleted that much faster.

    Unfortunately Runts and plain fish grow quickest !. Showa, Utsuri, Kohaku and Sanke seem to be slowest. Another reason why culling is so important.

    The growing on environment is also important since baby koi don’t grow well in man made filtered ponds because of a lack of natural food and are vulnerable to pollutants in water especially nitrite.



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