This species was isolated from freshwater pond here in Perlis, Malaysia. Unfortunately, I'm not certain about the name for this species. The size of this microalgae in range 2.5-3.5 micron. Is this Oocystis sp.?
I would key through genus in something like "freshwater algae" by G.W. Prescott for starting point. The image is not clear enough for anyone to help on species and even genius is very questionable. Maybe provide a better photo if available.