PRELIMINARY STUDIES ON THE ROLE OF PROTOZOA IN THE FOOD WEB OF DONGHU LAKE
佚名
【期刊名称】《中国海洋湖沼学报(英文版)》 【年(卷),期】2000(018)003
【摘要】Plankton from Station I of Donghu Lake, an eutrophic lake, was divided into three groups (2-32 μm, 32-112 μm and >112 μm) by filtering the water sample through 2, 32, 112 μm pores. It was supposed that the 2-32 μm Protozoa (group 1) was fed on by the 32-112 μm Protozoa and small rotifers (group 2) and >112 μm large rotifers, cladocerans and copepods (group 3). The feeding rate of zooplankton in situ was estimated by counting the protozoan individuals and also by the 14C-NaHCO3 method. The P/B ratio of the small Protozoa (group 1) was 2.9 for 6 h and 1.2 for 24 h. The feeding rate of the 32-112 μm zooplankton on small Protozoa (2-32 μm) was about 2/3 the total feeding rate of zooplankton, and that of >112 μm zooplankton on the 2-32 μm Protozoa was 1/3 of the total feeding rate. The lower the density of feeders, the higher were the feeding rates. The daily production of the 2-32 μm protozoans was 1.559 mg/L, which equaled to 25% of the daily food consumption of other zooplankton. Isotope experiments showed result similar to that from the above direct counting method.