IOUSP

Marina Tonetti Botana
Orientador – Paulo Yukio Gomes Sumida
Apresentação: 01 de dezembro, 5ª feira, as 9h00
Anfiteatro “Profa. Dra. Anna Emilia Amato de Moraes Vazzoler”

Physiological response of evolutionary divergente Symbiodinium clades (A!-D1) to alterations in seawater physical-chemical parameters

TF-2016/16
Marina Tonetti Botana
Symbiodinium are photosynthetic dinoflagellates that can be found in two different life stages. Most commonly, they are associated with a host in a mutualistic relationship. Alternatively, they can also be found in the water column as free-living cells. Only recently, the Symbiodinium genus was divided into 9 different clades which, as endosymbionts, present distinct tolerance levels to fluctuations in abiotic parameters (i.e., light, temperature and pH). However, there is still a lack of information about the free-living stage for each clade. Here we studied the population growth rate responses of free-living Symbiodinium clades (A1-D1) to individual changes in seawater pH, calcium and distinct light conditions. Although Ca2+ experiments were only performed for clades A1 and B1, we noticed that all clades presented distinct growth rate responses and boundaries to pH and light availability. Results provided a mechanistic understanding of Symbiodinium clades growth and they are complementary for host-symbiont research. Understanding Symbiodinium responses facilitates projections of possible distributional and population structure changes in face of current climate change scenarios (i.e., ocean acidification, stratification of the mixing layer, higher light availability). Key words: Carbonate chemistry, Symbiodinium, coral-reefs, physiological response, mechanistic understanding.