I need help for this identification.
I think it's a cyanobacteria (maybe an Oscillatorial?) but maybe it's a bacterium.
This taxon is filamentous and the dimensions of the cells are:
* Diameter = 1 - 1.5 microns
* Length = 8 - 23 microns and the majority about 16 microns
The lake Juslibol is a "Galacho", an old meander of the river Ebro (Spain).
This lake has a specific conductivity of about 5000 microS/cm and pH of 8 units.