The microflagellate-picoplankton food linkage in the water column of Lake Biwa
The microflagellate-picoplankton food linkage in the water column of Lake Biwa
复制标题
琵琶湖水体中微鞭毛虫-超微型浮游生物的食物联系
DOI：
10.4319/lo.1988.33.4.0504
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发表时间：
1988
影响因子：
4.5
通讯作者：
T. Nagata
中科院分区：
文献类型：
--
作者：
T. Nagata
1984年5月至11月，在日本琵琶湖北部的一个深水区（水深-72 m），对异养微鞭毛虫（HMF）、细菌和单细胞色球藻蓝藻（UCB）的丰度和生物量进行了季节性变化的研究。HMF、细菌和UCB的细胞密度为102- 103、10 - 10和102- 10 5个细胞ml-1，生物量估计值为< 1-7、10 -70和<1 -20 pg C升-1. HMF食物泡的显微镜观察表明HMF对UCB的主动吞噬作用;当UCB密度高时，高达52%的HMF细胞含有一个或多个UCB细胞。大小分级的epilimnetic沃茨的培养表明，细菌净生产率（5-25皮克C升-“d-m”）通常几乎等于HMF种群消耗细菌的速率。估计的总增长效率的HMF喂养天然picoproconflankton为1升-53%的碳。HMF可能是将微型浮游生物能量传递给不能采集微型浮游生物的大型浮游动物的重要环节。然而，由于缺乏关于HMF命运的信息，很难直接解决关于琵琶湖微生物循环的“汇与链”争论。
Seasonal variations of abundance and biomass of heterotrophic microflagellates (HMF), bacteria, and unicellular chroococcoid cyanobacteria (UCB) at a pelagic site (water depth, -72 m) in the north basin of Lake Biwa were measured during May to November 1984. The cell densities of HMF, bacteria, and UCB were 102-1 03, lo”, and 102-lo5 cells ml- I, and the biomass estimates were < 1-7, 1 O-70, and < l-20 pg C liter - I. Active phagocytosis of UCB by HMF was indicated from microscopic observation of HMF food vacuoles; when UCB density was high, up to 52% of HMF cells contained one or more UCB cells. Incubation of size-fractionated epilimnetic waters indicated that bacterial net production rates (5-25 pg C liter-’ d-m’) were usually almost equal to rates of consumption of bacteria by HMF populations. Estimates of gross growth efficiencies of HMF fed on natural picoplankton were 1 l-53% in terms of carbon. HMF may be a significant link transferring picoplankton energy to macrozooplankters which cannot collect picoplankton. Lack of information on the fate of HMF makes it difficult, however, to directly address the “sink vs. link” argument about the microbial loop in Lake Biwa.