Mixotrophy in Argentina freshwaters

B. MODENUTTI,

Freshwater Phytoplankton from Argentina

Schweizerbart Science Publishers

Año: 2014;

Mixotrophic organisms appeared in photosynthetic and heterotrophic lineages (i.e., algaeand ciliates). In this article we will present examples and discuss diverse aspects of the success ofthis dual nutrition mode in different lakes from Argentina. Factors as nutrients, light, water mixingintensity, mixing depth, and prey abundance have large effects on the ecological dynamics of theseorganisms. Traditional studies suggested that the growth rate of mixotrophic protists would dependon light intensity and prey abundance allowing the classifi cation of mixotrophs into different groups.We will discuss this scheme in the scenario of protists currently present in Argentina. Additionally, wewill examine the results of fi eld and experimental studies in Argentina lakes regarding the differentco-occurring factors that determine the success of different mixotrophic species. In particular, we willfocus competitive interactions among mixotrophs in nature, evaluating both, photosynthetic effi ciencyas a result of the niche partitioning along the water column and the ingestion of picoprokaryotes forfood niche overlap. Furthermore, we will present other studies on the relative importance of light(intensity and quality) in the autotrophy and phagotrophy balance.