I put the shiro fry into two places - a small sample went into a discreet vat, and the remainder went into the fry pond.
Numbers of fry in the fry pond had been dwindling, particualarly after the 1st week and then more by the end of the second week. Soon after - we could barely find any - the following weekend I did some final checks before making the decision to empty the pond. Turns out that was the right thing to do, as the whole batch had dissappeared.
Strange then that the sample of shiro fry in a separate vat are doing fine. And this is the silver lining because it means I can learn more about what to do with the hatchlings that are white but with just a small amount of black on them. They're a couple of weeks at the most away from harvest.
The fact the sample batch did ok helps to limit the number of things that could have led to the desimated stock in the fry pond. I think in the end, the pond just wasnt right for them - probably a lack of rotifers in the crucial week. That would explain why the fish in the sample vat were larger, even after a week or two outside.
To convey how delicately balanced this timing can be - I put the kohaku fry out into the other fry pond just one week later than when the shiro fry were introduced. And they're doing amazingly well! The only difference between the fry ponds was 1 week - the pond the shiro's went in was filled 1 week earler, and was ready 1 week earlier than the other pond.
We had our CEFAS compliance visit the other day. They are here primarly to check compliance with our biosecurity measures plan and to look for signs of notifiable diseases - the whole thing went fine, and it also gives us the chance to pick their brains on a wide range of things - the inspectors see so many fish farms, they are a fantastic source of experience.
Picture from the last couple of weeks
|A pile of cleaning, just waiting to happen.... The next spawning will be in around a month's time.|
I need to go through final selections on my 2014 tosai, but a broken UV has delayed things somewhat. And, It's also a job I don't really want to do. I need another pond....
|The UV on my growing on tanks isnt working, and the water has gone as green as pea soup. I've repaired the UV and hopefully it will clear in time for next weekend - when I'll be taking my home bred kohaku's out to the South Downs Koi Show.|
Kohaku fry in their fry pond - the haze is daphnia. Google's stacked a few photos of the same view on top of each other which gives the semi-movie feel. It's a test of this new format... the fry are doing really well, and my main concern is that the pond may be overstocked. From a visual check - there are more fry in the pond now than at the equivalent stage during the May 14 spawning.
I've adjusted the husbandry of the kohaku fry to take account of the larger than normal numbers in the pond - we've started feeding slightly earlier, and sligthly more than for the May 14 spawning. I'll need to keep an eye on things ....
And here's some video of the kohaku fry: