Food rationing affects dietary selenium bioaccumulation and life cycle performance in the mayfly Centroptilum triangulifer
Food rationing affects dietary selenium bioaccumulation and life cycle performance in the mayfly Centroptilum triangulifer
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DOI：
10.1007/s10646-011-0722-1
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发表时间：
2011-11-01
期刊：
影响因子：
2.7
通讯作者：
Buchwalter, D. B.
中科院分区：
文献类型：
--
作者：
Conley, J. M.;Funk, D. H.;Buchwalter, D. B.
硒在自然界中的作用是由初级生产者和较小但关键的饮食转移到初级消费者的相对较大的硒水溶液生物浓缩介导的。这些基础过程然后通过食物网传播到更高的营养级。在这里，我们量化的运动溶解硒（亚硒酸盐）的附着生物，并使用由此产生的附着生物作为食物来源进行全生命周期的饮食硒暴露的蜉蝣Centroptilum triangulifer。在溶解的硒浓度范围为1.1至23.1 μ g L-1的对数线性方式从溶液中的Periphyton生物浓缩硒类似于2,200倍。我们研究了两个喂养口粮水平（1x和2x）的营养转移，组织硒浓度，母体转移，和功能性端点的蜉蝣性能的影响。喂食较低口粮（1x）的蜉蝣显示出比喂食2x口粮（平均TTF，1.1 +/- 0.3）的蜉蝣更大的营养转移因子（平均TTF，2.8 +/- 0.4）。在1x暴露中，当膳食[Se] >= 11.9 μ g g g（-1）时，蜉蝣的存活率和总体重显著降低（p < 0.05），当膳食[Se] >= 4.2 μ g g g（-1）时，总繁殖力降低，当膳食[Se]>= 27.2 μ g g g（-1）时，发育延迟。蜉蝣喂养更大的口粮（2x）显示减少组织硒浓度（显然是通过生长稀释）相对于1x蜉蝣，没有显着影响的性能。这些结果表明，硒对蜉蝣的性能在自然界中的影响可能与食物资源的可用性和质量。此外，在将实验室得出的毒性估计值应用于野生种群风险评估时，营养状况是一个重要的考虑因素。
Selenium effects in nature are mediated by the relatively large bioconcentration of aqueous Se by primary producers and smaller, yet critical, dietary transfers to primary consumers. These basal processes are then propagated through food webs to higher trophic levels. Here we quantified the movement of dissolved Se (as selenite) to periphyton, and used the resultant periphyton as a food source for conducting full life-cycle dietary Se exposures to the mayfly Centroptilum triangulifer. Periphyton bioconcentrated Se similar to 2,200-fold from solution in a log-linear fashion over dissolved Se concentrations ranging from 1.1 to 23.1 mu g L-1. We examined the influence of two feeding ration levels (1x and 2x) on trophic transfer, tissue Se concentrations, maternal transfer, and functional endpoints of mayfly performance. Mayflies fed a lesser ration (1x) displayed greater trophic transfer factors (mean TTF, 2.8 +/- 0.4) than mayflies fed 2x rations (mean TTF, 1.1 +/- 0.3). In 1x exposures, mayflies exhibited significant (p < 0.05) reductions in survivorship and total body mass at dietary [Se] >= 11.9 mu g g(-1), reduced total fecundity at >= 4.2 mu g g(-1), and delayed development at >= 27.2 mu g g(-1). Mayflies fed a greater ration (2x) displayed reduced tissue Se concentrations (apparently via growth dilution) relative to 1x mayflies, with no significant effects on performance. These results suggest that the influence of Se on mayfly performance in nature may be tied to food resource availability and quality. Furthermore, nutritional status is an important consideration when applying laboratory derived estimates of toxicity to risk assessments for wild populations.