Department of Biology, Carleton University, 209 Nesbitt Bldg, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
Sci Total Environ. 2010 Oct 15;408(22):5439-44. doi: 10.1016/j.scitotenv.2010.07.071. Epub 2010 Aug 24.
Endoparasites can alter their host's heavy metal concentrations by sequestering metals in their own tissues. Contracaecum spp. (a nematode), but not Drepanocephalus spathans (a trematode), were bioaccumulating mercury to concentrations 1.5 times above cormorant hosts. Nematodes did not have significantly greater stable nitrogen isotope values (δ(15)N) than their hosts, which is contradictory to prey-predator trophic enrichment studies, but is in agreement with other endoparasite-host relationships. However, Contracaecum spp. δ(13)C values were significantly greater than their hosts, which suggest that nematodes were consuming host tissues. Nematodes were accumulating and thus sequestering some of their cormorant hosts' body burden of methyl mercury; however, they were not dramatically reducing their hosts' accumulation of methyl mercury.
内寄生虫可以通过将金属蓄积在自己的组织中来改变宿主的重金属浓度。拟指环虫（一种线虫）而非棘隙吸虫（一种吸虫）将汞蓄积到比鸬鹚宿主高 1.5 倍的浓度。线虫的稳定氮同位素值（δ(15)N）与宿主没有显著差异，这与猎物-捕食者营养富集研究相矛盾，但与其他内寄生虫-宿主关系一致。然而，拟指环虫的δ(13)C 值显著大于其宿主，这表明线虫正在消耗宿主组织。线虫在蓄积甲基汞的同时，也将部分蓄积在自己体内，从而将鸬鹚体内的甲基汞转移到自己体内；然而，它们并没有显著减少宿主对甲基汞的蓄积。
