A small omnivorous bitterling fish (Acheilognathus macropterus) facilitates dominance of cyanobacteria, rotifers andLimnodrilusin an outdoor mesocosm experiment
A small omnivorous bitterling fish (Acheilognathus macropterus) facilitates dominance of cyanobacteria, rotifers andLimnodrilusin an outdoor mesocosm experiment
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在户外中生态实验中，一种小型杂食性苦鱼（Acheilognathus macropterus）促进了蓝藻、轮虫和Limnodrilus的优势
DOI：
10.1007/s11356-020-08774-5
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发表时间：
2020
影响因子：
5.8
通讯作者：
Jeppesen Eri K.
中科院分区：
文献类型：
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作者：
Yu Jinlei;Xia Manli;Kong Ming;He Hu;Guan Baohua;Liu Zhengwen;Jeppesen Eri K.
小型杂食性鱼类往往在亚热带浅水湖泊中占主导地位，它们可能在至少两个营养级上影响水生生物的群落结构。然而，在亚热带湖泊水生食物网的研究中，大多数生态学家都关注大型杂食性物种（如鲤鱼）的影响，而对小型物种的研究很少。我们进行了两种处理（有鱼和没有鱼）的中生态实验，以研究小型杂食动物苦鱼（Acheilognathus macropterus）对浮游植物、浮游动物和底栖大型无脊椎动物的影响。我们的结果表明，苦味鱼的存在显着增加了浮游植物的叶绿素浓度和生物量，其中蓝细菌（主要是束丝藻属）占主导地位，占浮游植物总丰度和生物量的 99% 以上。在有鱼存在的处理中，浮游动物的丰度和生物量也较高，但小轮虫占主导地位，浮游动物与浮游植物的生物量比下降，表明对浮游植物的放牧减少。此外，在存在苦味的处理中，底栖大型无脊椎动物（tubificids）的丰度和生物量均高于对照组，这与杂食性鱼类（例如鲫鱼）占主导地位时发现的情况相反。反过来，较高的水管生物量可能会导致较高的沉积物养分释放。我们的研究表明 A.巨翼鱼，也许还有其他苦味物种，可以通过自上而下和自下而上的控制效应改变浮游和底栖组合，并导致富营养化湖泊中的水变得更加浑浊。因此，在亚热带浅水湖泊的恢复和管理中应更加关注这些小型杂食物种。
Small omnivorous fish often dominate in subtropical shallow lakes, and they may affect the community structure of aquatic organisms on at least two trophic levels. However, in the study of aquatic food webs in subtropical lakes, most ecologists have focused on the effects of large-sized omnivorous species (e.g. common carp), studies of small-sized species being scarce. We conducted a mesocosm experiment with two treatments (fish presence and absence) to examine the effects of a small-sized omnivore, bitterling (Acheilognathus macropterus), on phytoplankton, zooplankton and benthic macroinvertebrates. Our results showed that bitterling presence significantly increased the chlorophyllaconcentration and biomass of phytoplankton, which became dominated by cyanobacteria (mainlyAphanizomenonspp.) that accounted for >99% of both total phytoplankton abundance and biomass. Both the abundance and biomass of zooplankton were also higher in the fish-present treatment, but small rotifers became dominant, and the zooplankton:phytoplankton biomass ratio decreased, indicating less grazing on phytoplankton. Moreover, both the abundance and biomass of benthic macroinvertebrates (tubificids) were higher in the bitterling-present treatment than in the controls, which is opposite to the situation found when omni-benthivorous fish (e.g. crucian carp) dominate. Higher biomass of tubificids may, in turn, result in higher sediment nutrient release. Our study suggests thatA. macropterus, and maybe also other bitterling species, can alter both pelagic and benthic assemblages via both top-down and bottom-up control effects and lead to more turbid water in eutrophic lakes. Thus, more attention should be paid to these small omnivorous species in the restoration and management of shallow subtropical lakes.