[Nature of the afterglow of marine algae]

Excitation spectra and light curves were studied in three species of marine algae at monochromatic light excitation of the second-range afterglow. It was shown that light curves were satisfactorily described by an equation similar to the equation of enzyme catalysis with low light intensity of half-saturation (about 0.5 W X m-2). Shapes of the excitation spectra and spectral curves of quantum yield of the second-range afterglow was analysed considering the early non-linearity of its light curves. It was found that the results obtained and the literature data on a relatively high quantum yield of the second-range afterglow in the region of absorption of long-wave pigment system (above 680 nm) can be explained by the non-linearity mentioned above, not suggesting a participation of PSI in the generation of this afterglow.