North Wales Koi Club Forum

After again failing in attempts to spawn my big Isa Showa I decided to try kohaku this year, red and white should make a change from having all black and white fish last year.

After nothing happened the first night the koi were kept overnight in the spawning pond and it all happened on the second morning.

The koi I've used are as follows:
A 75cm female kohaku bred by Momotaro (koi on left)
A 75cm male kohaku bred by Yamamatsu (To look at this koi you would think it was female)
A 60cm male kohaku bred by exclusive
A 55cm male Showa bred by Sakuma (Just added to the mix out of interest)

After spawning ended the koi were returned to my main pond. The eggs have been treated with malacite green which i've found helps stop fungus from forming on any unfertilised eggs.

The pictures below show the parent koi and spawing taking place. I'm afraid the pictures aren't great but my excuse is it was raining quite heavily at the time and the light was terrible. It's now just a case of waiting a few days to see what hatches,

Colin

Fingers crossed for you Colin - although not a great Kohaku fan I would be interested to see how they turn out

Day 2

First thing is to check how many eggs were fertilised. The unfertilised eggs are already showing up as opaque white dots whilst the fertilised eggs are fairly clear and much harder to see. As you can see on the photo there seems to be plenty of fertile eggs.
Next task is to check the water quality as spawning koi play havoc with the water quality, results as follows:

Temp 21C
Am 0.49
Ni 0.5
pH 7.3

Not too bad after suddenly giving the filter 4 spawning koi to cope with. Carry out approx 10% water change and add more filter media from the main pond filter. (This is when K1 comes into it's own)

The recent cold weather has meant that even though the pond is heated the temperature is a bit lower than the usual 24 C so it'll probably be a couple more days before the fry start hatching.

Last thing to do today is to start preparing brine shrimp so that when the fry do hatch I'll have something to feed them with,

Colin

Great Stuff Colin,
Will be nice to see how they turn out,if the parents are anything to go by, should have some good'uns.Just a matter of culling the right ones LOL
keep posting the photos.

Dave.

Day 5

Most of the fry hatched overnight. Tens of thousands can be seen clinging to the pond walls. Start feeding with a mixture of brine shrimp and egg yolk although the fry are probably still living off their egg sacks at the moment.

Will leave it another day for any stragglers to hatch out and then will have to clear the infertile eggs before they start to putrify.

Colin

Fasinating Colin, I'll follow this thread with great interest. That must be some sized blue bowl with fish in it of that size. Look forward to the next installment.

Ian

Day 7

The fry are now 3 days old and as you can see from the photo, they're not very big. The penny is 20 mm in diameter so I guess the fry are around 7 mm long at present.
Water parameters:

Temp 23 C
pH 7.3
Am 0.15
Ni 0.4

The nitrite is still much higher than I would like but it's now fallen from it's peak of 1.5 two days ago. I've carried out something like 30% water changes for the last two days and spent most of yesterday cleaning the spawning brushes and vacuming the pond bottom to remove the infertile eggs.

Brine shrimp production is now in full swing and at present the fry are being fed on a combination of brine shrimp (freshly hatched and dry) and dried egg yolk 5 or 6 times a day.

It's now a case of keeping a close eye on the water quality and heavy feeding until the koi grow large enough to carry out the first cull in about a month's time.

Colin

Colin,

What will you be looking for in the first cull, deformities etc or have they already been culled?

Ian

Ian,

First thing is to keep as many fry alive as I can for another couple of weeks and then start to think about culling.

I'll then be looking to cull any deformed fish plus any others that are all white or all red. With my current set up a considerable number of fry are going through the bottom drain into the settlement chamber so I sort of sift through the numbers on a daily basis once they grown enough to see if they have some sort of pattern. I'll post some more photos once the fry grow a little more,

Colin

Day 14

I've photographed some of the fry again. In the 7 days since the previous photo some have almost doubled in size whilst others have barely grown at all.

My experiment of including a male showa in the spawning seems to have been a failure with only about 1 in 100 fry being dark and therefore potential showa.

I'm currently having to syphon the settlement chamber clean on a daily basis due to the amount of waste food being present, sifting through the debris for fry is very time consuming. I'll be glad when the fry grow a bit more and start taking floating food which should cut down on the waste.

Colin