Wang Feiyue, Goulet Richard R, Chapman Peter M
Environmental Science Program and Department of Chemistry, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.
Chemosphere. 2004 Dec;57(11):1713-24. doi: 10.1016/j.chemosphere.2004.07.050.
The freshwater amphipod, Hyalella azteca, is widely used in laboratory sediment toxicity and bioaccumulation tests. However, its responses in the laboratory are probably very different from those in the field. A review of the literature indicates that in its natural habitat this species complex is primarily epibenthic, derives little nutrition from the sediments, and responds primarily to contaminants in the overlying water column (including water and food), not sediment or porewater. In laboratory sediment toxicity tests H. azteca is deprived of natural food sources such as algal communities on or above the sediments, and is subjected to constant light without any cover except that afforded by burial into the sediments. Under these constraining laboratory conditions, H. azteca has been reported to respond to sediment or porewater contamination. In nature, contamination of overlying water from sediment is less likely than in the laboratory because of the large, generally non-static sink of natural surface water. H. azteca does not appear to be the most appropriate test species for direct assessments of the bioavailability and toxicity of sediment contaminants, though it is probably appropriate for testing the toxicity of surface waters. Toxic and non-toxic responses will be highly conservative, though the latter are probably the most persuasive given the exposure constraints. Thus H. azteca is probably a suitable surrogate species for determining sediments that are likely not toxic to field populations; however, it is not suitable for determining sediments that are likely toxic to field populations.
淡水双甲目动物阿兹特克透明溞广泛用于实验室沉积物毒性和生物累积测试。然而，它在实验室中的反应可能与在野外的反应大不相同。文献综述表明，在其自然栖息地中，该物种复合体主要生活在底栖生物之上，从沉积物中获取的营养很少，并且主要对覆盖水柱（包括水和食物）中的污染物做出反应，而非沉积物或孔隙水。在实验室沉积物毒性测试中，阿兹特克透明溞被剥夺了自然食物来源，如沉积物上或沉积物上方的藻类群落，并且除了被埋入沉积物中所提供的遮蔽外，它处于持续光照且没有任何遮盖的环境中。在这些受限的实验室条件下，据报道阿兹特克透明溞会对沉积物或孔隙水污染做出反应。在自然界中，由于天然地表水这个大的、通常非静态的汇，沉积物对上覆水的污染比在实验室中可能性更小。阿兹特克透明溞似乎不是直接评估沉积物污染物生物有效性和毒性的最合适测试物种，不过它可能适合测试地表水的毒性。毒性和非毒性反应会非常保守，尽管考虑到暴露限制，后者可能最具说服力。因此，阿兹特克透明溞可能是确定对野外种群可能无毒的沉积物的合适替代物种；然而，它不适合确定对野外种群可能有毒的沉积物。
