Very nice pictures indeed. Thank you!
This is not Diaphanosoma but Sida crystallina. They are much alike. They belong to the same Family: Sididea.
In the first picture, the blue part on the back of its head is a horseshoe-shaped nuchal organ with which Sida can stick to waterplants or the sample-glass. Diaphanosoma does not have such a big organ on the back of its head.