Grazing in the heterotrophic dinoflagellate Oxyrrhis marina: size selectivity and preference for calcified Emiliania huxleyi cells

Abstract

Selective grazing on nanophythoplankton by the heterotrophic dinoflagellate Oxyrrhis manna was investigated in laboratory expenments. 0. marina was offered 2 mixtures of differently sized algae: (1) Micromonas pusiUa (2 pm Equivalent Spherical Diameter), Emihania huxleyi (5 pm ESD), and Tetraselrms sueclca (7 pm ESD); and (2) Nannochloris sp. (2 pm ESD), Isochrysis galbana (5 pm ESD), Rhodomonas sp. (8 pm ESD). and Tetraselmis sp. (10 pm ESD)