Effects of Deposited Sediment on Patch Selection by two Grazing Stream Invertebrates
Effects of Deposited Sediment on Patch Selection by two Grazing Stream Invertebrates
复制标题
沉积物对两种放牧溪流无脊椎动物斑块选择的影响
DOI：
10.1007/s10750-005-5323-7
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发表时间：
2005
期刊：
影响因子：
2.6
通讯作者：
A. Suren
中科院分区：
文献类型：
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作者：
A. Suren
由两种常见的新西兰溪流无脊椎动物，蜗牛Potamopyrgus antipodarum和蚂蚁Deleatidium sp.对不同食物类型覆盖的鹅卵石的斑块选择，有和没有沉积沉积物。(Leptophlebiidae)，进行了定量化。每个分类群暴露在鹅卵石中，覆盖着(1)丝状绿藻(FGA)或硅藻，(2)硅藻或异养生物膜。每种食物类型都使用了两块鹅卵石，其中一块被沉积的沉积物污染。所有的鹅卵石都被嵌在小盆地的灰泥中，以防止动物隐藏在它们下面，并将已知数量的动物放入每个盆地。随着时间的推移，每只动物的位置都会被记录下来，并在黑暗中进行一些观察，看看这是否会影响动物的运动。在FGA覆盖的鹅卵石上发现的藻类比在硅藻覆盖的鹅卵石上发现的更多。覆盖有FGA的受沉积物污染的鹅卵石也比覆盖着硅藻的未受污染的鹅卵石支持更多的蜗牛。在被硅藻覆盖的鹅卵石上发现的藻类比在生物膜上发现的更多，沉积物降低了它们对这两种食物的偏好。在硅藻覆盖的鹅卵石上发现的鱼腥藻若虫比在FGA覆盖的鹅卵石上发现的多。底泥降低了Deleatidium对硅藻的偏好，但在含有底泥污染的硅藻的鹅卵石上发现的动物比未受污染的FGA更多。在被硅藻或生物膜覆盖的鹅卵石之间，斑块的选择类似，但沉积物降低了这两种食物对Deleatidium的偏好。在黑暗中，更多的Deleatium被记录在裸露的石膏上，这表明它们在夜间更具机动性，并正在寻找新的栖息地。这些结果有助于解释为什么在排水发达集水区的溪流中常见的藻类，其中FGA水华和沉积沉积物常见，而在排水欠发达集水区的溪流中，Deleatidium的常见出现，其中FGA和沉积物沉积不常见。
Patch selection for cobbles covered by different food types, with and without deposited sediment, by two common New Zealand stream invertebrates, the snail Potamopyrgus antipodarum (Hydrobiidae) and the mayfly Deleatidium sp. (Leptophlebiidae), was quantified. Each taxa was exposed to cobbles covered by (1) filamentous green algae (FGA) or diatoms, and (2) diatoms or heterotrophic biofilms. Two cobbles of each food type were used in each trial, one of which was contaminated by deposited sediment. All cobbles were embedded in plaster in small basins to prevent animals hiding under them, and a known number of animals placed into each basin. The location of each animal was recorded over time, with some observations being made during darkness to see whether this influenced animal movement. More Potamopyrgus were found on cobbles covered by FGA than cobbles covered by diatoms. Sediment-contaminated cobbles covered with FGA also supported more snails than uncontaminated cobbles covered with diatoms. More Potamopyrgus were found on cobbles covered by diatoms than biofilms, and sediment reduced their preference for both these foods. More Deleatidium nymphs were found on diatom-covered cobbles than FGA-covered cobbles. Sediment reduced the preference of Deleatidium for diatoms, but more animals were found on cobbles with sediment-contaminated diatoms than uncontaminated FGA. Patch selection was similar between cobbles covered by either diatoms or biofilms, but sediment reduced the preference of both these foods to Deleatidium. More Deleatidium were recorded on bare plaster during darkness, suggesting they were more mobile at night and searching for new habitats. These results help explain the common occurrence of Potamopyrgus in streams draining developed catchments where FGA blooms and deposited sediment are common, and of Deleatidium in streams draining less developed catchments where FGA and deposited sediment are uncommon.