This is it! Eventually, the alevins have hatched! The very cold weather back in November/December has certainly been responsible for the delay but we got there in the end! The death rate has been very reasonable too with probably a dozen ova and 4 alevins out of 130 eggs. The grid at the bottom of the tank has been removed to give way to gravel which provides the alevins with shelter from the current generated by the water pump. We have even been able to observe the hatching process as an alevin was wriggling out of its egg shell!
Check these other pictures!
https://blogs.glowscotland.org.uk/or/public/TrootintheShed/uploads/sites/108/2011/02/101_2283.jpg
https://blogs.glowscotland.org.uk/or/public/TrootintheShed/uploads/sites/108/2011/02/101_2291.jpg
Hi boys, do you remember noticing white foam at the surface of the tank at the beginning of the week, just when most of the ova had hatched? I found out that it is caused by the breakdown of the egg casing by enzymes (not by Fairy liquid as you suspected!)
Keep up the good work and check for dead alevins.
Mr. P