Population changes of Daphnia caused by declined calcium concentration: Evidences from population dynamics and sexual reproduction
Population changes of Daphnia caused by declined calcium concentration: Evidences from population dynamics and sexual reproduction
复制标题
钙浓度下降引起的水蚤种群变化：来自种群动态和有性生殖的证据
DOI：
10.1016/j.ecoenv.2022.113352
复制
发表时间：
2022
影响因子：
6.8
通讯作者：
Zhou Yang
中科院分区：
文献类型：
--
作者：
Jing Huang;Zihang Wang;Bo Yu;Yunfei Sun;Lei Gu;Lu Zhang;Yuan Huang;Zhou Yang
淡水钙的下降已成为高钙需求水蚤新的环境应激源，但对低钙胁迫下水蚤的种群动态和有性繁殖仍缺乏深入的了解。为了从种群水平评估钙含量下降对溞的影响，我们将两个无性系溞（CH和SH）分别暴露于不同钙浓度（0.5、1.0、1.5、5.0、10.0、25.0 mg L−1）中30天，并记录种群指标。结果表明，在1.0 mg L−1钙浓度下，CH无性系的总生物量、个体平均干重、虻总数、静息卵总数比25 mg L−1钙浓度下分别下降了75.5%、34.0%、83.6%和77.6%，而在1.0 mg L−1钙浓度下的SH无性系则下降了75.5%、34.0%、83.6%和77.6%。分别为 64.6%、26.1%、94.5% 和 82.2%。重要的是，与 25 mg L−1 钙相比，1.0 和 1.5 mg L−1 钙的 CH 克隆干溞群体中的 Ca 含量下降了 32.7% 和 6.7%，1.0 mg L−1 和 1.5 mg L−1 钙的 SH 克隆也分别下降了 30.9% 和 10.5%。此外，低钙显着降低了 ephippia 的周长和表面积。有趣的是，通过扫描电镜观察发现，低钙使ephippia的表面发生了变化。钙下降对水蚤种群和有性繁殖的负面影响将不可避免地危及物种和基因在种群水平上的持续存在。
The decline in freshwater calcium has become a new environmental stressor toDaphniawith high calcium demand, however, the population dynamics and sexual reproduction ofDaphniaunder low calcium stress are still lack of deep understanding. To evaluate the impact of declined calcium onDaphniafrom population level, we respectively exposed two clones ofDaphnia pulex(CH and SH) to different calcium concentrations (0.5, 1.0, 1.5, 5.0, 10.0, 25.0 mg L−1) for 30 days and recorded the population indicators. Results showed that total biomass, average dry weight per individual, total number of ephippia, total number of resting eggs ofDaphnia pulexCH clone at 1.0 mg L−1calcium decreased by 75.5%, 34.0%, 83.6%, and 77.6% compared with those at 25 mg L−1calcium, while SH clone at 1.0 mg L−1calcium decreased by 64.6%, 26.1%, 94.5%, and 82.2%, respectively. Importantly, Ca content in dryDaphnia pulexpopulation of CH clone at 1.0 and 1.5 mg L−1calcium decreased by 32.7% and 6.7% compared to those at 25 mg L−1calcium, and SH clone at 1.0 mg L−1and 1.5 mg L−1calcium also decreased by 30.9% and 10.5%, respectively. Furthermore, low calcium significantly decreased the perimeter and surface area of ephippia. Interestingly, observation by scanning electron microscope found that low calcium changed the surface of ephippia. The negative impact of calcium decline onDaphniapopulation and sexual reproduction will inevitably endanger the persistence of species and genes at meta population level.