The winter weather where we live has not followed the normal flow. It's been warmer than usual, we've had very few frosts. A light sprinkling of snow only once, and it didn't last even a single day.
And in March, the weather is taking it's time in warming up too.
Signs of spring are there, but thin on the ground. I usually wait until the frogs have spawned before preparing the outdoor fry ponds - but so far (and it's 27th March today), I've seen no frogs! this time last year, and we had hundreds of the little things and bucket loads of frog spawn. This year, nothing.
The thing is - I like to wait until after the frogs have done their stuff before relining - so that I can get rid of all the frog spawn before putting a nice clean liner in, and I don't want tadpoles galore in the fry ponds.
If I wait any longer before emptying, relining, and then filling the fry ponds, then they won't be ready for an early May spawning.
|Pump in, and 24 hours later I will be puncturing the liner where there are puddles and then it will be time to put the new liner over the top of the old one.|
So, I've started pumping out one of the ponds, and I'll follow with the other one next week. We have the new liners arriving next week and I'll get them lined and filling then. It's later than last year, but it will have to do.
I've taken all the tanks in the polytunnel through a series of treatments to knock back any looming parasites, and I've started raising the temp on my females tank slowly. I'm aiming for an early May spawning. Debate is underway in the Byer household on which female to lead off with this year. The tried and tested pairing? Or, 'sharkey' ( a highly volumous Momotaro kohaku), or 'Elle Macpherson' (a very long, Takigawa kohaku). Current thinking is to hold back the tried and tested kohaku for a late summer spawning, and go with something new to start with. All three kohaku females appear to be carrying eggs, and I will need to check them over nearer to the spawning time to see which ones are ready to spawn - and that will influence the choice.
Last year, we did reasonably well in the spawning vat and produced lots of hatchlings; the problem was converting them into 1 inch fry for first selection. This year, we are going to use some of the techniques we experimented with last year - like rearing the hatchlings for an extra week within a very fine hole size cage net , held within the fry pond - and we'll also try rearing fry in the polytunnel in tanks like these, with a filter attached.
I've set myself two targets for this year:
1 ) rear 100k fry to 1st selection from 1 spawning
2 ) rear fry from several different kohaku spawnings, to gain insight into alternative brood set combinations
Objective 2, should be possible. Each year I've been able to rear at least a decent sample number of fry to 1st selection from 2 spawnings. But Objective 1 is going to be really tough - it's almost double the number of fry I've produced to first selection in all 3 of the previous years , combined!
I've set Objective 1 because I think that's the key to me being able to push on with my overall project objectives; which is to rear my own home bred koi and win competitive show prizes with them.
In theory - it will be possible , if:
- I can repeat one of the good spawning, fertilisation and hatching performances from the last few years
- Use both fry ponds for one spawning; if both fry ponds actually work this time... then that should get me half way to my 100k target
- the other 50k fry will need to be reared using alternative means; and many hobbyists are having success rearing thousands of fry in small recirculation systems. So, I have 3 of those in the polytunnel and the hope is that these will make up the last 50k for my target. I have no experience raising fry in this way - this year will be my first go at it.
Finally, a brief update on tank situation in the polytunnel. I've had some help from John Stevens over the last couple of months to upgrade a few things. And one of the most exciting additions is a new recirculation tank that will be connected to the growing on system. We had to move the green vortex a few inches to make space for the new tank... and burying the pipes has also provided us with unobstructed walk ways around the green vortex tank too. A big improvement!
Writing this - mid morning, late in March; and we have thunder and lighting outside; and it's absolutely chucking it down. That's the kind of weird weather we're experiencing this year....