Shiba river is one branch of Fuji river's basin. I thought it should take about half hour by car from our house, but actually it took an hour.
After she enjoyed her bike time, we started to check this river.
Under the stone which was turned over, we found several nymphs of aquatic insects there.
I think this is one of Hirata family. This type is called 'Clinger type', which means it attaches itself to the back side of stone and not good at swimming. As you see, it has flat body.
On the other hand, this type is called as 'Swimmer type'. As its name itself, it is just good swimmer.
I guess this is Kokagerou's(Baetis) one.
There are all sorts of nymphs. I likely need more knowledge and learning. Should keep my eyes peeled.