I am not sure if they are mating but I believe the intention is there. I had never seen this before. Another prove that microscopy is a hobby without limits. There is always something new to find.
Now I still have to sort out which of these many appendages are the naughty bits. And hopefully I will be able to find out which species this is. Water flea species often look very similar.
Images made through a microscope. All subject types.