Increased filtration efficiency of attached compared to free-swimming flagellates

摘要: Heterotrophic flagellates often attach to surfaces while feeding. A possible fluid dynamic reason is that attachment increases filtration efficiency. This was investigated experimentally and theoretically. The effect of on flow field clearance studied by video microscopy in the nanoflagellates Paraphysomonas vestita Pteridomonas danica. around feeding cells visualised latex bead suspensions. From a dynamics point view, it advantageous be sessile if radius transectional area water swept for particles smaller than 1.5 × cell radius. For with smooth flagellum, this also requires flagellum beats large amplitude. attached P. vestita, ca. 70% higher relative free-swimming danica value 34%. difference between 2 species accords fact sweeps wider its size Paraphysomonas. Protozoa may other reasons, such as remain at sites high food concentrations, but case suspension feeders, terms dynamics. It likely proportion heterotrophic plankton are associated suspended act drift anchors, thus enhancing clearance.