Golden algae - Uroglena
Uroglena colony is remarkable with the big round mucilage form including a lot of cells. The single cell is without covering of any form (they are naked), but have two flagella and the whole colony is moving in the water.
The colonies make a fish-odour and fish-taste on the water. Uroglena is quite common in water poor of nutrients, together with Synura and Dinobryon.