Experimental Ecological Study On Feeding And Growth Of Marine Heterotrophic Flagellates

Heterotrophic flagellates are of free-living protists moving and/or feeding by the use of flagella and feeding exclusively by heterotrophic means or, if with plastids, then also capable of ingesting particles. This group is characteristic by having small cell volume, high metabolic rate, and high diversity in terms of species. Heterophic flagelates are common and abundant in most natural habitats. They are consumers of pico-phytoplankton, hetero-bacteria and some organic detritus in marine environment, and thus play an important role in cycle of matter and energy flow. Morevoer, their ecological features are closely related to the eutrophication process in seawater. The biological and ecological importance of heterotrophic flagellates is one of highlight field in the study of microbial ecology.The culture, isolation and purificaiton of heterotrophic flagelltates are the basis of other in-depth study. Current methods for isolation of hetertrophic flagellalte in-clude serial diluition method, dipping-wire separation method, micromanipulatory separation method. A modified method on the basis of micromanipulatory separation method was adopted in our study, which had the advantate of being easy to master and handle. By using this modifided method, 10 species of heterotrophic flagellate, some of which has a proxiamte diameter of 3μm, were isolated from seawater sample col-lected from different sites. The morphological and life style of these flagelaltes are described here. However, identificaiton of these species has not been carried out be-cause of the shortage of relevant classificaiton information.The feeding of heterotrophic flagellates plays an important role in microbial process. Many approaches are employed in in situ and laborotory analysis of the grazig rate and each has its own advantages and disvantages. Metabolic inhibitor method and fluoresent labeled bacteria (FLB) method were used in our study. In the former study, penicillin was employed and strongly inhibited the growth of bacteria. The clearance rate of heterotrophic flagellates (XM-1) under two food concentration were 4.56 nl/ind/h and 2.83 nl/ind/h, the grazing rate were 6.40 bacteria/ind/h and...