Survivals of D. galeata in sub-tropical reservoirs: harmful effects of toxic cyanobacteria in food source
Survivals of D. galeata in sub-tropical reservoirs: harmful effects of toxic cyanobacteria in food source
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亚热带水库中 D. galeata 的存活：食物来源中有毒蓝藻的有害影响
DOI：
10.1007/s10646-012-0940-1
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发表时间：
2012-08-01
期刊：
影响因子：
2.7
通讯作者：
Gu, Jiguang
中科院分区：
文献类型：
--
作者：
Han, Bo-Ping;Lin, Xian;Gu, Jiguang
在本研究中，我们验证了蓝藻作为食物来源的大量出现是限制浮游动物银河蚤在中国南部温暖水域水库分布的因素之一的假说。用蛋白核小球藻、4株蓝藻(3株铜绿微囊藻：MC1、MC2、MC3)和1株假鱼腥藻进行饲养试验。：PA)，蛋白核葡萄球菌和蓝藻菌株的混合物，以及最初收集动物的水库中的天然颗粒物。在中、高摄食水平(1和1.5mgC·L-1)下，斑潜蝇为典型的III型存活，种群内禀增长率较高(0.37~0.41)。在低食物水平下，人口的内在增长率下降，但寿命大大增加(84天)。当摄食天然颗粒时，内禀增长率明显降低(0.19)，但最大体长(2 Mm)比野外观察到的个体长得多，这表明银纹夜蛾受到大小选择性捕食者的强烈捕食。应用小球藻和蓝藻的混合物，蓝藻的菌株和比例显著影响动物的生活史变量和体细胞生长。在每一株蓝藻的单一饲料上，D·galeata都无法繁殖。微囊藻毒素和微囊藻菌株的菌落形态降低了卵子大小和体细胞生长速度。相比之下，菌株MC3的负面影响较小，表明这种形态对浮游动物实际摄取有毒蓝藻至关重要。Pusoanabaena sp.有一根短丝(15亩米)，可以很容易地作为食物被金线莲食用。浮游植物群落的组成对马尾藻的生存和种群规模有重要影响，蓝藻水华的大量发生限制了马尾藻在中国南部水库的分布。
In the present study, we tested the hypothesis that massive occurrence of cyanobacteria as food source is one of the factors limiting the distribution of the zooplankton Daphnia galeata in the warm water reservoirs of South China. D. galeata was fed with Chlorella pyrenoidosa, 4 strains of cyanobacteria (three strains of Microcystis aeruginosa: MC1, MC2 and MC3, and one strain of Pseudoanabaena sp. :PA), a mixture of C. pyrenoidosa and cyanobacterial strains, and natural particles from the reservoir where the animal was initially collected. On medium and high food levels (1 and 1.5 mg C L-1) of C. pyrenoidosa, D. galeata showed a typical Type III of survivorship, and had a high intrinsic rate of population increase (0.37-0.41). On low food levels, the intrinsic rate of population increase declined but lifespan largely increased (84 days). When feeding with natural particles, the intrinsic rate of increase was evidently reduced (0.19), but the maximal body length (2 mm) was much longer than that of individuals observed in the fields implying that D. galeata was strongly preyed upon by size-selective predators. Applying a mixture of Chlorella and cyanobacteria, the strain and proportion of cyanobacteria significantly affected life history variables of the animal and its somatic growth. On the sole diet of each stain of cyanobacteria, D. galeata failed to reproduce. Microcystin and colonial morphology of Microcystis strains reduced clutch size and somatic growth rate. In comparison, the less negative effect of the strain MC3 indicates that the morphology was critical for actual ingestion of toxic cyanobacteria by the zooplanktons. Pseudoanabaena sp. had a short filament (15 mu m), can be easily used as a food by D. galeata. Composition of phytoplankton community plays a significant role in survival and population sizes of D. galeata and massive occurrence of cyanobacterial blooms limits the distribution of D. galeata in the reservoirs of South China.