PDF(Pubmed)
Abstract：
BACKGROUND: Salinity, exacerbated by rising sea levels, is a critical environmental cue affecting freshwater ecosystems. Predicting ecosystem structure in response to such changes and their implications for the geographical distribution of arthropod disease vectors requires further insights into the plasticity and adaptability of lower trophic level species in freshwater systems. Our study investigated whether populations of the mosquito Culex pipiens, typically considered sensitive to salt, have adapted due to gradual exposure.
METHODS: Mesocosm experiments were conducted to evaluate responses in life history traits to increasing levels of salinity in three populations along a gradient perpendicular to the North Sea coast. Salt concentrations up to the brackish-marine transition zone (8 g/l chloride) were used, upon which no survival was expected. To determine how this process affects oviposition, a colonization experiment was performed by exposing the coastal population to the same concentrations.
RESULTS: While concentrations up to the currently described median lethal dose (LD50) (4 g/l) were surprisingly favored during egg laying, even the treatment with the highest salt concentration was incidentally colonized. Differences in development rates among populations were observed, but the influence of salinity was evident only at 4 g/l and higher, resulting in only a 1-day delay. Mortality rates were lower than expected, reaching only 20% for coastal and inland populations and 41% for the intermediate population at the highest salinity. Sex ratios remained unaffected across the tested range.
CONCLUSIONS: The high tolerance to salinity for all key life history parameters across populations suggests that Cx. pipiens is unlikely to shift its distribution in the foreseeable future, with potential implications for the disease risk of associated pathogens.
METHODS: Mesocosm experiments were conducted to evaluate responses in life history traits to increasing levels of salinity in three populations along a gradient perpendicular to the North Sea coast. Salt concentrations up to the brackish-marine transition zone (8 g/l chloride) were used, upon which no survival was expected. To determine how this process affects oviposition, a colonization experiment was performed by exposing the coastal population to the same concentrations.
RESULTS: While concentrations up to the currently described median lethal dose (LD50) (4 g/l) were surprisingly favored during egg laying, even the treatment with the highest salt concentration was incidentally colonized. Differences in development rates among populations were observed, but the influence of salinity was evident only at 4 g/l and higher, resulting in only a 1-day delay. Mortality rates were lower than expected, reaching only 20% for coastal and inland populations and 41% for the intermediate population at the highest salinity. Sex ratios remained unaffected across the tested range.
CONCLUSIONS: The high tolerance to salinity for all key life history parameters across populations suggests that Cx. pipiens is unlikely to shift its distribution in the foreseeable future, with potential implications for the disease risk of associated pathogens.
摘要：
背景：盐度，海平面上升加剧了，是影响淡水生态系统的关键环境线索。预测响应这种变化的生态系统结构及其对节肢动物疾病媒介地理分布的影响，需要进一步了解淡水系统中低营养级物种的可塑性和适应性。我们的研究调查了蚊子淡色库蚊的种群，通常被认为对盐敏感，由于逐渐暴露而适应。
方法：进行了中观实验，以评估生活史特征对三个种群沿垂直于北海海岸的梯度增加的盐度水平的响应。使用了至微咸-海洋过渡区的盐浓度（8g/l氯化物），没有预期的生存。为了确定这个过程如何影响产卵，通过将沿海人口暴露于相同的浓度进行定植实验。
结果：尽管在产卵过程中，浓度达到目前描述的中位致死剂量（LD50）（4g/l）令人惊讶，即使是盐浓度最高的治疗也偶然定植。观察到种群之间发育率的差异，但是盐度的影响仅在4g/l或更高时才很明显，导致仅延迟1天。死亡率低于预期,在盐度最高的情况下，沿海和内陆人口仅达到20％，中等人口仅达到41％。在整个测试范围内，性别比例不受影响。
结论：人群对所有关键生活史参数的高耐性表明Cx。在可预见的未来，Pipiens不太可能改变其分布，对相关病原体的疾病风险有潜在的影响。
方法：进行了中观实验，以评估生活史特征对三个种群沿垂直于北海海岸的梯度增加的盐度水平的响应。使用了至微咸-海洋过渡区的盐浓度（8g/l氯化物），没有预期的生存。为了确定这个过程如何影响产卵，通过将沿海人口暴露于相同的浓度进行定植实验。
结果：尽管在产卵过程中，浓度达到目前描述的中位致死剂量（LD50）（4g/l）令人惊讶，即使是盐浓度最高的治疗也偶然定植。观察到种群之间发育率的差异，但是盐度的影响仅在4g/l或更高时才很明显，导致仅延迟1天。死亡率低于预期,在盐度最高的情况下，沿海和内陆人口仅达到20％，中等人口仅达到41％。在整个测试范围内，性别比例不受影响。
结论：人群对所有关键生活史参数的高耐性表明Cx。在可预见的未来，Pipiens不太可能改变其分布，对相关病原体的疾病风险有潜在的影响。
