Shiro utsuri kuroku

I feel like a proper koi breeder with my first kuroku completed this weekend.

The whirring and whining of the vacuum pump, lots of people sat around a table with plastic cups - some filled with fresh water, others with koi fry. Lots of airline, and a calm and focussed faces from friends and family that came over at short notice to help us through it. That's what it's like.

A BIG thankyou to Andy Corrie, Mark Dickinson, Mick Guttridge and Allan Dean - who all came over at really short notice on a bank holiday Monday to help out.

Here's the general principal - in a shiro utsuri spawning, the hatchlings are either black or white. The black ones will develop sumi, and may develop into shiro utsuri - and the white ones will not.

This is based on the advice I've taken, and experiences of others - and we've collected a few sample shiro hatchlings and put them into a separate tank to check the results; this is focussed on the hatchlings that are bascially white, but with a tiny amount of black on them. So, not completely white and also not completely black.

After a day and a half of kuroku, we still had several 10's of thousands of unsorted fry left; we timed out, and introduced them to the pond without being sorted.

The feeling today among the helpers was 70% to 80% of the fry are black. That's much higher than when I looked on Saturday - and perhaps it's just that we now have a much larger sample. Or perhaps more fry developed their black between Saturday and today (Monday). Either way - I'm very happy about the stat because it bodes well for the spawning. If I wanted to be increadibly positive then I'd say it was my new shiro male that was involved in the spawning a week ago that changed the balance to 70%/80% from the 30%/40% black fry that we experienced the last time we spawned this female.

The fry pond they've gone into is experiencing a daphnia bloom - and although a little early, it looks spectacular and I remember the May kohaku spawning went the same way last year and we had a great harvest. lets hope it works that way again for the shiro's.

Here's a set of photo's that gives you an idea of what we've been up to.

And, a few video's :

Shiro's in the bowl:

Kuroku - and you can tell why we're all wearing ear defenders once you listen to this: