University of Georgia's Savannah River Ecology Laboratory, Aiken, SC, 29802, USA.
Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA.
Ecotoxicology. 2024 Mar;33(2):164-176. doi: 10.1007/s10646-024-02736-0. Epub 2024 Feb 8.
Mercury (Hg) is a ubiquitous environmental contaminant known to bioaccumulate in biota and biomagnify in food webs. Parasites occur in nearly every ecosystem and often interact in complex ways with other stressors that their hosts experience. Hepatozoon spp. are intraerythrocytic parasites common in snakes. The Florida green watersnake (Nerodia floridana) and the banded watersnake (Nerodia fasciata) occur syntopically in certain aquatic habitats in the Southeastern United States. The purpose of this study was to investigate relationships among total mercury (THg) concentrations, body size, species, habitat type and prevalence and parasitemia of Hepatozoon spp. infections in snakes. In the present study, we sampled N. floridana and N. fasciata from former nuclear cooling reservoirs and isolated wetlands of the Savannah River Site in South Carolina. We used snake tail clips to quantify THg and collected blood samples for hemoparasite counts. Our results indicate a significant, positive relationship between THg and snake body size in N. floridana and N. fasciata in both habitats. Average THg was significantly higher for N. fasciata compared to N. floridana in bays (0.22 ± 0.02 and 0.08 ± 0.006 mg/kg, respectively; p < 0.01), but not in reservoirs (0.17 ± 0.02 and 0.17 ± 0.03 mg/kg, respectively; p = 0.29). Sex did not appear to be related to THg concentration or Hepatozoon spp. infections in either species. We found no association between Hg and Hepatozoon spp. prevalence or parasitemia; however, our results suggest that species and habitat type play a role in susceptibility to Hepatozoon spp. infection.
汞 (Hg) 是一种普遍存在的环境污染物，已知会在生物群中生物积累，并在食物网中生物放大。寄生虫存在于几乎每个生态系统中，并且经常与宿主经历的其他压力源以复杂的方式相互作用。肝孢虫属是常见于蛇类的红细胞内寄生虫。佛罗里达绿水蛇 (Nerodia floridana) 和带状水蛇 (Nerodia fasciata) 在东南美国的某些水生栖息地中同时出现。本研究旨在研究总汞 (THg) 浓度、体型、物种、栖息地类型以及蛇类肝孢虫属感染的患病率和寄生虫血症之间的关系。在本研究中，我们从南卡罗来纳州萨凡纳河场址的前核冷却水库和孤立湿地中采集了 N. floridana 和 N. fasciata。我们使用蛇尾夹来量化 THg，并采集血液样本进行血液寄生虫计数。我们的结果表明，在两种栖息地中，THg 与 N. floridana 和 N. fasciata 的蛇体大小之间存在显著的正相关关系。湾（分别为 0.22±0.02 和 0.08±0.006 mg/kg；p<0.01）中的 N. fasciata 的平均 THg 明显高于 N. floridana，但在水库中则没有（分别为 0.17±0.02 和 0.17±0.03 mg/kg；p=0.29）。性别似乎与两种物种的 THg 浓度或肝孢虫属感染无关。我们没有发现 Hg 与肝孢虫属感染的患病率或寄生虫血症之间存在关联；然而，我们的结果表明，物种和栖息地类型在对肝孢虫属感染的易感性方面起着作用。
