https://www.selleckchem.com/JAK.html Dissolved oceanic CO2 concentrations are rising as result of increasing atmospheric partial pressure of CO2 (pCO2), which has large consequences for phytoplankton. To test how higher CO2 availability affects different traits of the toxic dinoflagellate Alexandrium ostenfeldii, we exposed three strains of the same population to 400 and 1,000 µatm CO2, and measured traits including growth rate, cell volume, elemental composition, 13C fractionation, toxin content, and volatile organic compounds (VOCs). Strains largely increased their growth rates and particulate organic carbon and nitrogen production with higher pCO2 and showed significant changes in their VOC profile. One strain showed a significant decrease in both PSP and cyclic imine content and thereby in cellular toxicity. Fractionation against 13C increased in response to elevated pCO2, which may point towards enhanced CO2 acquisition and/or a downscaling of the carbon concentrating mechanisms. Besides consistent responses in some traits, other traits showed large variation in both direction and strength of responses towards elevated pCO2. The observed intraspecific variation in phenotypic plasticity of important functional traits within the same population may help A. ostenfeldii to negate the effects of immediate environmental fluctuations and allow populations to adapt more quickly to changing environments.Iningainema is a recently described genus of heterocytous, false-branching cyanobacteria originally described from Australia. In this work, we present Iningainema tapete sp. nov., isolated from subaerial and terrestrial environments in central Florida (USA). In comparison to the sister species, our novel cyanobacterium produces nodularin-R (NOD-R) and a methylated isoform [MeAdda3] NOD previously not reported within this genus; in addition to possessing the biosynthetic gene clusters for microcystin and anabaenopeptins production. Nodularin accumulation by this cyanobact