Suppliment: Parasitism of Bloom-Forming Dinoflagellates: Host Specificity and Ecological Implications

由有毒和无毒的甲藻引起的赤潮在全球范围内的蔓延日益引起人们的关注，研究兴趣集中在影响水华形成物种积累、持续和死亡的物理和生物相互作用上。赤潮对海洋动物造成的有害影响以及对公众健康和商业渔业的相关风险也引起了人们对检测、预测和潜在控制有害藻华的手段的兴趣。最近的研究表明，海洋环境中存在大量的微寄生虫，包括病毒、细菌和原生动物。此外，寄生虫引起的浮游细菌和浮游植物死亡可在几小时到几天的时间尺度上引起宿主丰度的种群水平变化。赤潮甲藻被它们的寄生近亲中华阿米巴感染与宿主种群的迅速下降有关。这种寄生虫也被认为是防止水华形成的一个重要因素。虽然所有这些对自由生活的甲藻的感染都被归因于一种寄生虫，但最近的数据表明，Ceratii是由多个宿主特有的寄生虫组成的物种复合体。这项研究将通过考虑切萨皮克湾赤潮形成的甲藻寄生与宿主专一性之间的相互作用，进一步加深对赤潮生态的认识。它还将有助于确定浮游系统中宿主-寄生虫相互作用的复杂性，并为寄生在微生物食物网动态中的作用提供新的见解。五个具体的假设将使用最先进的形态和分子方法进行测试。

Increasing concern over the global spread of red tides produced by toxic and non-toxic dinoflagellates has focused research interest on physical and biological interactions that influence the accumulation, persistence, and demise of bloom-forming species. The harmful effects imposed by red tides on marine fauna and associated risks to public health and commercial fisheries have also prompted interest in means to detect, predict, and potentially control harmful algal blooms. Recent studies have shown that microparasites, including viruses, bacteria, and protozoa, are abundant in marine environments. Furthermore, parasite-induced mortality of bacterioplankton and phytoplankton can cause population level changes in host abundance on time scales of hours to days. Infection of red-tide dinoflagellates by their parasitic relative Amoebophrya ceratii has been linked to rapid declines in host populations. This parasite has also been implicated as an important factor in preventing bloom formation. while all such infections of free-living dinoflagellates have been attributed to a single species of parasite, recent data suggest that A. ceratii is a species complex composed of multiple host-specific parasites. This research will further the understanding of red-tide ecology by considering the interplay between host specificity and parasitism of bloom-forming dinoflagellates in Chesapeake Bay. It will also help define the complexity of host-parasite interactions in planktonic systems and provide new insight on the role of parasitism in microbial food-web dynamics. Five specific hypotheses will be tested using state-of-the-art morphological and molecular methods.