catenella cells. “
“For cnidarians that can undergo

shifts in algal symbiont relative abundance, the underlying algal physiological changes that accompany these shifts are not well known. The sea anemone Anthopleura elegantissima associates with the selleckchem dinoflagellate Symbiodinium muscatinei and the chlorophyte Elliptochloris marina, symbionts with very different tolerances to light and temperature. We compared the performance of these symbionts in anemones maintained in an 8–11.5 month outdoor common garden experiment with simulated intertidal conditions and three levels of shading (2, 43, and 85% ambient irradiance). Symbiont densities, mitotic indices, photophysiology and pigments were assessed at three time points during the summer, a period of high irradiance and solar heating during aerial exposure. Whereas S. muscatinei was either neutrally or positively affected by higher irradiance treatments, E. marina responded mostly negatively to high irradiance. E. marina in the 85% irradiance treatment exhibited significantly reduced Pmax and chlorophyll EPZ-6438 cell line early in the summer, but

it was not until nearly 3 months later that a shift in symbiont relative abundance toward S. muscatinei occurred, coincident with bleaching. Symbiont densities and proportions remained largely stable in all other treatments over time, and displacement of S. muscatinei by E. marina was not observed in the 2% irradiance treatment despite the medchemexpress potentially better performance of E. marina. While our results support the view that rapid changes in symbiont relative abundance are typically associated with symbiont physiological dysfunction and bleaching, they also show that significant temporal lags may occur between the onset of symbiont stress and shifts in symbiont relative abundances. “
“A hyperspectral imaging camera was combined with a bright-field microscope to investigate

the intracellular distribution of pigments in cells of the green microalga Haematococcus pluvialis, a synonym for H. lacustris (Chlorophyceae). We applied multivariate curve resolution to the hyperspectral image data to estimate the pigment contents in culture and revealed that the predicted values were consistent with actual measurements obtained from extracted pigments. Because it was possible to estimate pigment contents in every pixel, the intracellular distribution of the pigments was investigated during various life-cycle stages. Astaxanthin was localized specifically at the eyespot of zoospores in early culture stages. Then, it became widely distributed in cells, but subsequently localized differently than the chl.