Mass development of Daphnia pulex in a sulfide-rich pond (Lake Cisó)
Mass development of Daphnia pulex in a sulfide-rich pond (Lake Cisó)
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富含硫化物的池塘（西索湖）中大量繁殖水蚤
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
C. Pedrós
中科院分区：
文献类型：
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作者：
J. Gasol;K. Jürgens;R. Massana;Juan I. Calderón;C. Pedrós
我们研究了两个多星期的衰减的蚤状蚤的人口，入侵了以前枝角类无epilimnion湖Ciso。在湖泊的含氧上层水层中发现的枝藻浓度高达1，900 ind l −1，而大部分可获得的食物都集中在上层水层中。D.在硫化物浓度高达1.2mM的浅水层中从未发现蚤状蚤。蚤状动物被迫进入静水层缺氧的下部。这些动物一天大部分时间都呆在水面上，尤其是在黎明时分，它们会下降到硫化物分布的上层。主要是1.3至1.9毫米大小的动物迁移。这种模式的人口流动有关的食物分布和氧气的配置文件，而不是其他因素通常牵连在浮游动物的垂直迁移（鱼类捕食是缺席）。在我们认为与群集行为相关的动物水平分布中有很强的变异性。在我们的研究期间，与第一周相比，在采样的后几周，动物的生育力指数较低，平均大小较高，表明种群数量下降
We studied over two weeks the decay of a population of Daphnia pulex that had invaded the previously cladoceran-free epilimnion of Lake Ciso. The cladoceran was found at concentrations up to 1,900 ind l −1 in the oxygenated epilimnion of the lake while most of the available food was concentrated in the metalimnion. D. pulex was never found in the hypolimnion with sulfide concentrations up to 1.2 mM. Probably due to the food distribution, D. pulex was forced to move into the anoxic lower part of the metalimnion. The animals spent most of the day at the surface, and descended especially at dawn to the upper level of the sulfide distribution. Mainly animals of sizes between 1.3 and 1.9 mm migrated. This pattern of population movement was related only to the food distribution and the oxygen profiles, and not to other factors commonly implicated in zooplankton vertical migrations (fish predation was absent). There was strong variability in the horizontal distribution of the animals that we associated to swarming behavior. During our study the population was in decline as shown by the lower indices of fetility and the higher mean sizes of the animals in the later weeks of sampling as compared to the first week