Distribution of Daphnia in a trade-off between food and temperature:: individual habitat choice and time allocation
Distribution of Daphnia in a trade-off between food and temperature:: individual habitat choice and time allocation
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DOI：
10.1111/j.1365-2427.2004.01260.x
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发表时间：
2004-09-01
影响因子：
2.7
通讯作者：
Kessler, K
中科院分区：
文献类型：
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作者：
Kessler, K
1.在深水藻类最多的温度分层水柱中，水蚤面临着食物(繁殖力高)和温度(快速发育)之间的权衡。最近的研究表明，水蚤种群在整个水柱上上下移动，以利用这两种水柱，但尚不清楚个体在特定食物和温度条件下分配给水母、水母和水母的时间比例。在一个1米深的垂直有机玻璃管系统中，我建立了表面(表层)和底层(底层)之间2、5和10度C差的三个温度梯度。将藻类加入到海藻中，模拟深水藻类的最大值。为了测量个体分配给不同垂直栖息地的时间比例，并评估它们在表层和下层之间转移的频率，对新生和产卵的透明水蚤个体的迁徙行为进行了监测。新生儿一直呆在表面，利用较高的温度，可能是因为蛋黄储备对他们来说喂养不那么重要。相反，产卵雌成虫在温度梯度较弱时，会花更多的时间在下界取食，但也会迁徙到下界，以利用较高的温度。在最陡峭的温度梯度中，产卵雌虫或在外膜和亚膜之间移动，或在中间条件下不断地栖息在金属膜中。
1. In a thermally stratified water column with a deep-water algal maximum, Daphnia face a trade-off between food (high fecundity) and temperature (fast development). Recent studies showed that Daphnia populations move up and down the entire water column to take advantage of both, but the proportion of time allocated by individuals to the epilimnion, metalimnion and hypolimnion with their specific food and temperature conditions is not yet known.2. In a system of 1 m deep, vertical perspex tubes, I established three temperature gradients with 2, 5 and 10 degreesC differences between the surface (epilimnion) and the bottom layer (hypolimnion). Algae were added to the hypolimnion to simulate a deep-water algal maximum.3. The migration behaviour of individual neonate and egg-bearing Daphnia hyalina x galeata was monitored in order to measure the proportions of time the individuals allocated to the different vertical habitats and to assess the frequency of their shifts between epilimnion and hypolimnion.4. Neonates stayed continuously at the surface, taking advantage of the higher temperature, possibly because feeding was less important for them because of egg yolk reserves. In contrast, egg-bearing females spent more time feeding in the hypolimnion when the temperature gradient was weak, but also migrated into the epilimnion to take advantage of the higher temperature. In the steepest temperature gradient, the egg-bearing females either shifted between epilimnion and hypolimnion, or dwelled constantly in the metalimnion with intermediate conditions.