Growth rate and main photosynthetic pigments monitoring via self-fluorescence spectra for Microcystis aeruginosa Kuetz. CALU 972. (a) – chlorophyll a fluorescence, excitation wavelength 440 nm, (b) – phycocyanin fluorescence, excitation wavelength 625 nm. Figures near curves denote the number of incubation days. Vertical lines indicate wavelengths for fluorescence maximum of corresponding photopigment.