Differing effects of suspended sediments on the performance of native and exotic Daphnia.
Differing effects of suspended sediments on the performance of native and exotic Daphnia.
复制标题
悬浮沉积物对本地和外来水蚤性能的不同影响。
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
J. Havel
中科院分区：
文献类型：
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作者：
Lori A. Soeken;James A. Stoeckel;J. Havel
总结
1.虽然大型枝角类在大型河流中通常并不常见，但龙氏蚤（Daphnia lumholtzi，北美的一种外来物种）分布广泛，偶尔数量也很丰富。 我们在伊利诺伊河（美国伊利诺伊州）采集浮游动物。在1995年和1996年，发现D. lumholtzi（25 L-1）通常超过所有本地物种的总和。最大密度出现在温暖时期（高达27 °C），此时无机悬浮沉积物的浓度很高（>50 mg L−1）。
2.采用生命表法研究了悬浮泥沙（0和80 mg L-1）和食物（104和105个锚定藻细胞mL-1）的变化对杜氏藻适合度的影响。 lumholtzi和原生水蚤parvula。隆氏蚤的存活率高于隆氏蚤。parvula在大多数处理中的生育力均高于D.所有治疗中的小孢子。这两个物种实现了最快的内在增长率高的食物治疗，但他们的反应悬浮固体不同。D.高浊度食品中的lumholtzi含量略有增加，而D. parvula很沮丧。
3.结果表明，D. lumholtzi容忍悬浮固体是一个重要因素，有助于其成功入侵北美河流。
Summary
1. Although large cladocerans are usually uncommon in large rivers, Daphnia lumholtzi (an exotic species in North America) is widespread and occasionally abundant. We collected zooplankton on the Illinois River (Illinois, U.S.A.) in 1995 and 1996 and found that the peak density of D. lumholtzi (25 L−1) typically exceeded that of all native species combined. Maximum density occurred during warm periods (up to 27 °C) when concentrations of inorganic suspended sediments were high (>50 mg L−1).
2. Using a life table experiment, we examined the effects of variation in suspended sediment (0 and 80 mg L−1) and food (104 and 105Ankistrodesmus cells mL−1) on fitness of D. lumholtzi and the native Daphnia parvula. Daphnia lumholtzi had greater survivorship than D. parvula in most treatments and higher life-time fertility than D. parvula in all treatments. Both species achieved their fastest intrinsic rates of growth in treatments with high food, but their responses to suspended solids differed. The growth rate of D. lumholtzi in high food was slightly increased by higher turbidity, whereas that of D. parvula was depressed.
3. Results suggest that the ability of D. lumholtzi to tolerate suspended solids is an important factor contributing to its success in invading North American rivers.