Siddall R, Sures B
School of Environmental and Applied Sciences, University of Derby, UK.
Parasitol Res. 1998 Jul;84(7):573-7. doi: 10.1007/s004360050451.
The uptake of lead by cystacanths of the acanthocephalan Pomphorhynchus laevis in naturally infected amphipods, Gammarus pulex, and by immature parasites in experimentally infected fish, Leuciscus cephalus, was examined following 3-week experimental exposures (0.01 and 0.1 mg l(-1) Pb2+). Both G. pulex and the cystacanths of P. laevis accumulated lead but concentrations in the parasites were lower than in the host tissues at the low lead dose and significantly lower at the high dose. P. laevis from chub exposed to 0.01 mg l(-1) lead contained significantly more of the metal than the tissues of their host. Interestingly, there was an increase in the mean lead levels in the parasites from the control chubs which was concurrent with a decrease in host tissue concentrations. The results of this experimental study therefore confirm previous suggestions that heavy metals are predominantly accumulated by acanthocephalans inside the fish definitive host and not by cystacanths in the haemocoel of the amphipod intermediate host. The microhabitat of the parasite is therefore of primary importance rather than its developmental stage. Furthermore, metal concentrations in adult acanthocephalans will respond rapidly to changes in environmental exposure of their hosts.
在为期3周的实验暴露（0.01和0.1 mg l(-1) Pb2+）后，研究了棘头虫平滑膨吻棘头虫（Pomphorhynchus laevis）的囊尾蚴在自然感染的双足类动物蚤状钩虾（Gammarus pulex）中以及未成熟寄生虫在实验感染的鱼类圆腹雅罗鱼（Leuciscus cephalus）中的铅摄取情况。蚤状钩虾和平滑膨吻棘头虫的囊尾蚴都积累了铅，但在低铅剂量下，寄生虫中的浓度低于宿主组织，在高剂量下则显著更低。暴露于0.01 mg l(-1)铅的雅罗鱼体内的平滑膨吻棘头虫所含的这种金属比其宿主组织中的显著更多。有趣的是，对照雅罗鱼体内寄生虫的平均铅含量有所增加，同时宿主组织中的浓度下降。因此，这项实验研究的结果证实了先前的推测，即重金属主要是由鱼类终末宿主体内的棘头虫积累，而不是由双足类中间宿主血腔中的囊尾蚴积累。因此，寄生虫的微生境比其发育阶段更为重要。此外，成年棘头虫体内的金属浓度将对其宿主环境暴露的变化迅速做出反应。
