Abstract JodŁowska S. and LataŁa A. 2010. Photoacclimation strategies in the toxic cyanobacterium Nodularia spumigena (Nostocales, Cyanobacteria). Phycologia 49: 203–211. DOI: 10.2216/08-14.1. This ecophysiological study of the planktonic cyanobacterium strain Nodularia spumigena (BA-15) was conducted at three photosynthetic active radiation (PAR) irradiances (10, 150, and 290 µmol photons m−2 s−1) and two temperatures (15 and 30°C). The filament concentration, pigment composition, and photosynthetic performance of N. spumigena depended on culture conditions. The cyanobacterium was very tolerant of the highest irradiance at the lower temperature (15°C). Filament concentration, however, was lower at the higher temperature and the highest irradiance compared with other culture conditions. The efficiency (α) and maximum rates of photosynthesis (Pm) were both affected negatively at 30°C under irradiances of 150 and 290 µmol photons m−2 s−1. The photoacclimation capacity of the cyanobacterium was evaluated by ...