Swimming speed of two phytoplankton species, Rhodomonas salina and Teleaulax sp., grown in nutrient replete F/2 medium and in P-limited conditions, as well as swimming speed of the heterotrophic dinoflagellate Oxyrrhis marina either starved or fed with these four types of phytoplankton individually. In addition to the different culture and feeding conditions, the phytoplankton and dinoflagellates were incubated with the water from differently cultured organisms.