Quantification of floating ephippia in lakes: a step to a better understanding of high dispersal propensity of freshwater plankters
Quantification of floating ephippia in lakes: a step to a better understanding of high dispersal propensity of freshwater plankters
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湖泊中漂浮的 ephippia 的量化：更好地了解淡水浮游生物的高扩散倾向的一步
DOI：
10.1007/s10750-015-2437-4
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发表时间：
2015
期刊：
影响因子：
2.6
通讯作者：
B. Pietrzak
中科院分区：
文献类型：
--
作者：
M. Ślusarczyk;T. Grabowski;B. Pietrzak
Daphnia属的浮游枝角类是一种在水生生境中传播的生物，其传播能力仅限于传播休眠卵，这些卵被封装在称为ephippia的保护结构中。在本研究中，我们的目的是量化生产的浮动和下沉ephippia在湖泊中测试的假设，即使他们最终下沉，他们中的大多数是第一次浮在水面上。此外，我们还检查了胚胎的卵含量状况。这项研究的结果显示，浮在湖面上的石藻数量在石藻生产时达到每平方米数千只，并构成了该生产的很大一部分。在所研究的浅低地湖泊和在山湖，大多数ephippia首先浮在水面，而在深低地湖泊的比例是相反的。大约一半的ephippia最初出现在水面沉没在六个星期的采样期间。卵内容物状态没有不同的浮动和下沉ephippia。在山湖中，有大量的雌鱼在夜间停留在表层，并对雌鱼进行了实验室研究，结果表明，雌鱼在怀孕期间会主动向水面产卵。
Planktonic cladocerans of the genusDaphniaare an example of organisms whose ability to disperse among aquatic habitats is limited to dispersal of dormant eggs, encapsulated in protective structures called ephippia. In the present study, we aimed to quantify the production of floating and sinking ephippia in lakes to test the hypothesis that, even if they eventually sink, most of them are first floating at the surface. In addition, we checked the egg content status of the ephippia. The results of this study revealed numbers of ephippia floating at lakes surface reaching thousands per square metre at the time of ephippia production, and constituting substantial share of that production. In studied shallow lowland lakes and in a deep mountain lake, most ephippia were first floating at the water surface, while in deep lowland lakes the proportion was reversed. Approximately half of ephippia that appeared initially at the water surface sank during the six-week sampling period. The egg content status did not differ between floating and sinking ephippia. High numbers of ephippial females staying in the surface layers at night in a mountain lake, and a laboratory experiment with ephippial females indicated that ephippia are actively oviposited to the water surface by gravid females.