I found two different algae, both coming from freswater shallow ponds (not the same), and I do not know what species they belong to.
1. Regarding the first photo, I thought it was a fragment of Volvox, but I can't see any flagela, and there are not any connection among cells either. I thought of something similar to Tetraspora after, but in that case I would have expected the cells to be in tetrads.
2. Regarding the second photo, I think it may be Cladomonas but I am not sure at all.
I would be very grateful if you could help me to identify any of them.
Kind regards.
Gonzalo Martín