Koi Experimental Spawning

Experimental Spawning.

This is a little experiment I am carrying out to see if I can successfully spawn and raise koi earlier in the year. Tank raising them until the weather allows them to be placed in the mud ponds.

At my holding facility in Wrington I set up a heated tank with Metal Halide lighting above. In this was placed a 2mtr x 1mtr x 1mtr floating net with spawning brushes attached along each side.

This morning (25/03/03) the experimental spawning began.

The parents are koi of no value, but had very good skin quality before loosing their beni. They are all small, but held on to them so I could play and learn.

Female a Matsunosuke Goromo, males kohaku, one from Sakuma, the other of unknown origin.

On arriving this morning they had spawned to some degree, but had lost total interest. I watched for 20 minutes and there was no chasing, they were just feeding on the few eggs around the side of the floating net equipped with spawning brushes.

As the female still had many eggs I decided I would have a go at artificial spawning. I have no experience of this and should have done some research, but it was not planed so had to take the moment.

I removed the female with care as eggs were flowing. I anaesthetised her, dried her in a towel and then carefully stripped her eggs into a foil container (the only thing that was around). I did the same with the males and stripped their milt directly into the container on top of the eggs. I mixed the milt with a pencil and left it for a minute. I think the next step is where I went wrong?

I knew that when the eggs come into contact with water they swell and become sticky. I was nervous of this and swilled the eggs onto the water above the spawning brushes, making sure they had all separated as they sunk onto the brushes.

After I had finished I then did a little research on the Internet and found I perhaps should have introduced a little water to the eggs and milt and mixed this and waited for another minute or so. This it seems would still of left enough time before the eggs became sticky?

If these hatch, I shall attempt to raise them on newly hatched brine shrimp. The cultures of these I need to get up and running within a couple of days.

Are they fertile? Will this be successful? Only time will tell.

Malachite green was added the next morning at standard rate of 25ml of 30% solution per 880 gallons. This will stop infertile eggs becoming covered in fungus.

27/03/03 The photo below shows how the eggs are doing. The white one's are infertile, hopefully looking at the number of opaque eggs compared to white ones my hand stripping has worked?

27/03/03 Malachite Green was added again. Little eyes can just be seen in the eggs.

28/03/03 On inspection early Friday morning many eggs could be seen with a little tail protruding, these are around 3mm long and as yet shown no signs of the yellow/orange colour of kohaku or goromo fry, just white. With the air turned off they can be seen wiggling at times, so there's life within!

A couple of photos of eggs with little tails. Quality is poor as this was stretching the macro facility of my camera.

29/03/03 Around one third of the eggs are gone from the spawning brushes and have fallen to the bottom of the tank. They are still white looking in colour. On wafting a fine mesh net just over the bottom they appear to be gripping on and the only catch was a few that were obviously dead, though fully formed fry. Fingers crossed by tomorrow they may be free swimming.

I'm surprised that they are not showing the expected colour as yet. The youngest fry I saw last year were coloured up yellow, but these were just free swimming. I hope they are alive and well?

Sadly I slipped up and re-dosed the malachite too late, I have learned a lesson and shall only use malachite once in future. Unfortunately I sent an enquiry to Japan regarding dosing, but received the reply too late. The reply said that while as eggs malachite is fine, but once they start hatching it will kill them.

Attempt 2

17/04/03 I placed in the floating net 2 male showa that I bought in Japan in February, they are from an amateur breeder from Hiroshima. The female is from Miyatora in Niigata and looks to have come from a modern showa sanke cross as she has strong shiny sumi, good white ground, but suffers from some secondary Hi in single scale areas. But as this is an experimental spawning I an happy to use her as I am not risking my best Oyagoi.

The female this time was injected with CARP PITUITARY EXTRACT to induce spawning, 20% of the dose was injected as she went in with the males and the other 80% was injected 24 hours later.

Next morning 19/04/03 I arrived at Wrington at 6.30am, all was finished and there were eggs every where, none left in the female at all.

20/04/03 Malachite added.

21/04/03 Tails could be seen protruding from the eggs.

22/03/04 Most of the fertile eggs/fry had left the spawning bushes and where on the bottom. I noted this time with the natural spawning that the fertility rate was a lot lower than the hand stripped spawning.

Photo taken 22/04 of fry with egg sack.

23/04/03 Most fry still on the bottom, although some were clinging to the side of the net. Most of their egg sacks look used up.

The floating net that holds the spawning brushes and fry has a very fine mesh of 1mm. But fine as it is many fry have been seen outside of the net, so action had to be taken to stop the fry from being sucked into the filter pump. The standard filtration on the tank has been closed off as the bottom drain would slowly suck up the fry and send them to the filter, so a pump fed system was setup to pump to an above tank filter containing pre-matured K1 Kaldnes media. This is fed by a Blagdon 4,000, this has now been mounted in a tank with 250 micron screens to stop the fry being sucked to the pump.

24/04/03 The fry can be seen swimming to the top to take their first breath of air to inflate their swim bladders.

The fry will be fed on newly hatched brine shrimp and cultures to hatch these have been set up. Pictured below is 3 of the cultures made from 2 litre lemonade bottles.

When breeding showa, the first cull is very early and is carried out normally within the first few days. Only the black fry are kept and all the light coloured ones are culled. I shall keep a few of the light coloured ones to see the results.

The fry at the top of the photo is a black one the bottom is a light coloured one to be culled a little later.

25/04/03 Added brine shrimp for the first time this morning. They will be getting 3 feeds a day, I am told the newly hatched brine shrimp will stay alive for a few hours in fresh water, so in theory food should be available at all times as long as I add enough. On close inspection a short while after the first feed, small orange areas could be seen in the tiny gut of the fry, this is the colour of the brine shrimp, so many are feeding, this is nice to see.

I gently swooped a fine through the water to catch a few to look at and photograph, if you remember that with showa only the black fry are kept, you will see from the photo I have many to cull. From this shot there is only 7 to keep and 40 or so to cull. It seems that perhaps 2/3rd of the fry should go on first cull. But as this is an experiment and to keep the numbers up to a fairly high concentration, I will leave for now around 1/3rd of the light coloured fry. Reason for this is if this were a kohaku spawning, I would not be able to cull so early.

Later in the day the fry were seen to be shoaling up into groups, although there were still many hundreds staying close to the tank sides and a few in the middle that appeared to still be trying to take there first breath. Perhaps they won't make it?

In the photo below the orange colour of the brine shrimp can be seen inside the fry.

I decided to remove the floating net and release the fry into the main tank, as there were as many outside as there was inside! This was a task I wished I hadn't started and took me well over an hour to ensure all the fry were released and not caught up in the net.

27/04/03 All is going well, when the fry first hatched, there were a few dead ones floating on the surface which I scooped up, since then there have been none that I have seen.

There is noticeable growth and I'd estimate many are now around 12mm in length. There is already a size difference between large and small fry, it may be an illusion but the black ones seem to be growing at a faster rate, I expect this is due to being able to see the whole length of the fry, the orange coloured ones tend to be a little translucent towards the back end.

I have no idea as to the total number, but I'd hazard a guess at around 5,000. I have realized at this early stage it is not going to be cheap to raise the fry by this method, the brine shrimp eggs are being used at a tremendous rate. I have ordered more, this time 1/2 kilo, that is a fair few egg at 220,000 per gram.

Photos showing growth over 2 days, same camera settings, same place.

25/04/03 27/04/03

Below is a close up of the newly hatched brine shrimp with a 10mm fry to give size impression.

29/04/03 Fry doing very well, putting on size all the time though in length and not in body. The brine shrimp as food appears to be very good and can still be seen alive and swimming around in the tank some 6 hours after being put in for the fry. Because of this I have cut the feeds down to 2 a day. This will need increasing again as they grow larger and require more food.

01/05/03

It is becoming obvious that the food needs are changing at quite a rate as growth continues. After cutting the feeds down to 2 a day a change in behavior of the fry was noticed. When I put the brine shrimp in for a feed, I switch the filtration off for around half an hour, the fry during this period are all over the tank feeding. When I switch the filter back on the fry congregate at a point beyond the heavy flow of the filter return, I assume this is an area where feeding is easy as brine shrimp are washed to this area and the fry feed there. After the morning feed I occasionally switch off the filter and watch the surface of the water under the metal halide lighting, within a few minutes the brine shrimp start to mass under the light. I have been doing this to check there is always sufficient food for the fry.

However over the last couple of days it has been noticed that by midday the fry have left the sides of the tank where they normally stay and are all over. On turning off the filtration, no brine shrimp could be seen. I returned to giving a lunch time feed , after the filters were turned back on the fry slowly returned to their normal position around the edge, only to do the same thing later afternoon. It seems that as the brine shrimp are used up the fry then start hunting down the last few and are looking for food. Same thing happens when I arrive in the morning and after their feed return to the sides.

I have started siphoning the bottom of the tank to keep it as clean as I can. I used a top portion of a small lemonade bottle cut down, with a hose pushed through a drilled hole in the cap. I aim to remove around 50 gallons a day by siphoning and the top up with fresh water will be my water changes. Although most of the fry swim out of the way while I am siphoning the bottom, I have sucked up a few which I retrieve from the bowl I siphone into. This seems to do them no harm.

06/05/03

The fry are growing well, over the last couple of days many of the light coloured fry are starting to show sumi, this is quite a surprise and I did not expect this quite so soon. There are many growing at a faster rate and I assume these are what are called TOBIES, these are cannibals and eat their siblings. I have seen some chasing others and some with fry sticking out of their mouths. I will remove these to another tank, as and when I see extra large fry, but this is quite a task as they are in 1,200 gallons and are allover. There have been quite a few dead fry floating on the surface, I'm not sure if these have died or they are the remains of the sucked out cannibalized fry?

Reposted photo of fry taken 25/04/03 Photo to compare size as they are now 06/05/03

27/05/03

Photos taken in the same trimmed down drinking cup.

03/06/03

Time has flow by and growth on the fry is continuing. There is a noticeable difference in size between the biggest and smallest, I have continued to remove the larger Tobies/ shooters and now have in the region of 500 at around 40mm. The vast majority are in the 25-30mm range, but there are still many 15-20mm.

My early estimate of 5,000 fry was grossly underestimated, there are at least 10,000, sadly most will end up culled, as expected quality is not that good, but after all this is an experiment, at the outset I was not prepared to chance one of my better quality spawning and chance losing the lot.

Space is getting very tight, unfortunately the weather through May has been cold and wet. I had hoped to be able to put them out in a mud pond, but have had to keep them inside in wait of better weather. Over the last couple of weeks I have been catching them out of the large tank and splitting them into 3 groups, based on size, the plan being to try and give the smaller one's more chance and a little extra food. As they have continued to grow they are getting very over crowded and the time has come to send them to the mud pond. I shall be very glad, as the time and effort I have had to put into these little one's has been demanding to say the least.

So far only the deformities I have spotted have been culled and I have kept the numbers up as with any other spawning but showa, I would have to keep all until at least this time. There are a fair number, 25-30% that show just yellow/orange head and black body, I'm pretty sure all these will end up as culls, but I shall give them a couple of weeks to confirm as last year I did a trail spawn with Kinshowa and many had this black body, but at harvest there were none, so they may change, part of my learning! Which to cull?

The mud pond has been prepared as best I can, they are on very low ground and fill naturally with ground water, this makes it difficult with preparing the pond bottoms as I cannot successfully lime as the bottom soon fills with water, however I do my best and then fertilize with turkey manure. This was not done as far in advance as I would have liked because of the weather, which as said earlier has been very wet, but as the end of May arrived the sun came out and the water warmed well, so I took my chance and placed a couple of thousand in the pond to check if the fry could cope with the stronger than I would like water due to the fairly recent manuring of the pond. A few succumbed to the water, but the vast majority were fine so off to the mud pond go most, but not all.

I have separated out a couple thousand black body with yellow faces and kept them back here in a tank. Also the larger one's are still here, these will stay until I cull the pond in a few weeks. By that time hopefully most will have caught up in size and then the better one's from the tobies can go into the mud pond with their siblings.

Cost to raise them to six weeks old has been fairly close to £150.00. This experiment I feel has been most successful, I shall continue to update as and when there is anything to report, including the first real culling in a couple of weeks.

Photo below is of one of the large fry, it is starting to take on a showa pattern, not a show winner, but pleasing all the same.

This is one that got left behind in the tank some how, I'll put it in the mud pond and see how it turns out.

02/09/03

The showa fry have been in the small mud pond for a couple of months now. Space is limited and so growth has been compromised. Most of the fry are only a couple of inches long, with the best at 4", I'm sure this would have been much more given the room, but as these were not expected to be of any real quality they were only given the small pond.

Much to my surprise there are a few that show potential and will be kept to see the results. Last week I swooped in with the pan net on three occasions while feeding and returned to Wrington with the resulting bucket of koi. Each time I caught around 200 fry and decided I would cull out of each bucket the lowest quality 150, this left around 50 keepers per trip. These are being kept at Wrington to strengthen the filter ready for when I net all the ponds and return the best for indoor over wintering.

Of these approximate 150 I expect around 100 will be good enough for garden center outlets, around 10 or 15 I will keep and see how they progress, the rest will be culled when the time comes.

This photo is of one of the keepers with the potential to improve. It's one of my 'Tategoi'

During September and pond was netted with the seine net and most of the koi sorted. The net was only pulled through the pond once, so many escaped the selection process and they will spend the cold winter in the mud pond till spring when I shall drain the pond ready for use. I may have missed a few reasonable koi, I'll see come spring!

I culled through the netted tosai, any of garden centre quality and above where returned to my unit at Wrington. This leaves me with a total of around 500 (estimate), they are a variety of sizes up to 4", though many were smaller. This was due to the fact that they were placed in my smallest mud pond and I had to go careful with the amount of food they were given. The rest were carefully put to sleep in anaesthetic. You may say this is mean to end the life of these baby koi, but they have no resale value and if kept will stunt the growth of all as space is limited.

These babies, along with ones from the other spawnings will be kept this winter in heated water and grown on to a sellable sizes of 4". As the garden centre koi come up to 4" they will be moved on to a cooler tank, where they will be feed adequate food to sustain their health, but will not be looking for extra growth. This will leave more room for the better ones and give a chance for the smaller to catch up.

The photo below shows that the general grade of these showa is just 'pond mutts', but they will help to cover food costs.

A close up of a few of average quality, these all except one will end up at a garden centre come spring.

Updated 24/11/03. I'll add more in a while.