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Origins of the Koi Carp and how to breed these beautiful fish

Koi Carp are a fascinating fish that have been around for many years but have only been available to all over the last hundred years. The aim of all Koi keepers has to be the sight of fry in their fish ponds, sometimes this is planned but in most cases it is purely by no intervention of the keeper and the sight of the fry can come as a surprise.

The Koi Carp display wonderful markings and some specimens can demand very high prices if their markings are clear and of a certain colouration. But where did the Koi carp originate from in the first place and how did these beautiful markings come about in the first place.

The complete history of this fish is somewhat shrouded in mystery but there are certain facts that most people agree with.

Koi carp and the common goldfish are closely related but they are in fact two different species. The goldfish originate from the Crucian Carp (Carassius carassius) whereas the Koi Carp actually originate from the common carp (Cyprinus carpio). At one time it was believed that the Koi Carp originated from Japan, indeed they are sometimes known as the “Japanese Goldfish” but it is now known that the Koi Carp actually originated from China where they were first selectively bred for their markings. There are written records of this fish that date back to the year 200 AD but these are very vague and there is a large gap in the records up to the 1700's where records appear of the Japanese rice farmers would actually breed these fish in their paddy fields to provide food for their families through the difficult months between rice crops.

It didn’t take these farmers long to realise that certain specimens were display markings that were pleasing to the eye and these specimens were bred with other specimens of similar markings to pronounce the colours even further thus the start of the selective breeding to obtain the various species that we know today.

The Koi carp are now bred all over the world but there are recognised colourations and markings that are classified into sub-species of this fish and they all have recognised names that all breeders will be aware of and aim to produce the fish within these species with the best overall markings.

Japanese Koi Carp are indisputably the best quality Koi Carp available but there are other strains available such as the Israeli Koi Carp which to me seem to be of a lower quality and are not recognised as pure Koi Carp.

So how can I breed Koi Carp?

Breeding Koi Carp can be a bit hit and miss especially to a novice Koi keeper, the fish that you breed may not be of a perfect quality but the fact that you have bred them more than makes up for this. Do not be disillusioned that you can make a lot of money from breeding these fish, it will not happen unless you are a commercial breeder and the investment for becoming one of these can be large but for breeding these fish as a hobby there are several guidelines that should guarantee you some form of success in your own fish pond or even in a large enough aquarium if you are lucky enough to possess one. With all aspects of fish breeding, this activity takes a lot out of the fish especially the females, conditioning the fish beforehand will strengthen the parent fish and build up their immune systems. It is wise to rest the females in-between spawning sessions to allow them to rebuild their strength so that they are back to their peak before producing the next batch of fry.

The whole process begins with selecting the parent fish, they must be healthy specimens and males need to be at least 3 years of age while the females need to be slightly older, at least 4-5 years of age. After resting over the winter months the fish will be gradually brought back to a full feeding regime as the water temperature increases in the spring months, the conditioning of the fish means supplying them with lots of healthy food to build them up ready for the spawning sessions.

Spawning mops need adding to the fish pond, these can be commercial mops or you can even make you own by attaching lengths of yarn that has been boiled and these are simply floated on the water surface in one corner of the fish pond. The eggs will be laid on these when the time comes and makes life easier if you wish to move the eggs to another container straight after spawning.

How do I know if the fish are ready to spawn?

There are a couple of tell tale signs to let you know that spawning may be imminent, the Koi may suddenly start to refuse food or just eat less, this is not because they are ill but merely that they have other thoughts on their mind.

You may see three of the Koi swimming together in a triangle formation, this usually involves two males and one female and is quite common. The leading male is looking for suitable spawning sites and should head for the spawning mops.

When spawning is imminent the three fish will swim over the spawning mops and start to thrash about, witnessing this is amazing and sometimes worrying as the fish may appear to be behaving violently towards each other, they are not so allow them to carry on without disturbing them. Spawning normally takes place in the early morning and should be complete in approximately 1-2 hours, the spawning mops will be covered with eggs and now you need to act quickly before the other fish decide to make a meal of the newly laid eggs so the spawning mops will need to be moved to a separate vat or aquarium to prevent this.

Hatching the eggs and raising the fry!

The eggs need moving to a suitable container such as a small vat or am aquarium,whichever you choose the container must be clean and filled with aged pond water that are the same parameters as the pond where the fish spawned. A filter is not required initially but if you do add one, make sure that the intake filters are sealed with sponges or a fine mesh, if not the fry can easily be sucked inside the filter and will starve eventually. The water does need to be well oxygenated so the use of an air pump with an air stone is advised. Once the spawning mops are added, add a few drops of methylene blue, this will help to prevent the onset of fungus in the rearing tank or vat plus help with most other infections that could enter. Some of the eggs may be white and these are probably unfertilised, no young will be produced from these eggs so never expect a 100% hatch rate, it will never happen.

The eggs will take e3-4 days to hatch but do not feed the fry at this stage, newly hatched fry are classed as wrigglers, this means that they are not free swimming and they will consume their yolk sacs before requiring any food from the breeder. The fry should be free swimming a few days after hatching and adding aged pond water should supply them with enough food initially as it is full of minute organisms, far too small for the eye to see and these will sustain the fry for the first few feeds. Once you do start feeding the fry, offer small but regular meals, brine shrimp or Infusoria (Green Water) are ideal until the fry start to grow and then their appetite will increase so the meals should be enlarged to cope with this.

Now the bad part of fish breeding, culls will have to take place with the fry, some of the fry will be deformed, this is a natural process, and some will appear weaker than the others. Only the healthiest fry should be reared and as they will grow at different rates, you will find that they need size grading and splitting into different tanks to prevent the larger fry from out eating the smaller fry.

You may find that several culls are needed until you finish up with healthy stock and the actual number of fry that you wish to raise at the end of the breeding session, in a few months they will grow into juvenile fish and once large enough to look after themselves, accepting the same diet as their parents, they can either be moved on or added back to your fish pond!