Trophic Controls on the Life Cycle of Pfiesteria piscicida and the Second Known Toxic Pfiesteria-like Species

最近，潜在的微妙，但严重的慢性/亚致死性的影响，被称为有毒的Pfiesteria复杂的鱼类健康以及人类健康的dino-flagellates是在美国大陆上最大的河口，切萨皮克湾的几个支流的有毒爆发实现。 在切萨皮克爆发之前的近十年里，第二大河口Albemarle-Pamlico也发生了更大规模的鱼类死亡和动物流行病。 在拟议的研究中，我们将继续研究营养控制复杂的生命周期的Pfiesteria piscicida，并将延长类似的努力，以表征生命周期的第二个有毒Pfiesteria样的物种（尚未正式命名），最近被确定从纽斯和Pocomoke河口的Albemarle-Pamlico河口生态系统和切萨皮克湾，分别。 使用先进的视频成像和运动分析软件，我们将获得两种鱼类捕食者复杂生命周期中阶段转换的完整摄影记录，通过操纵可用的猎物（藻类，细菌，贝类，鳍鱼，哺乳动物组织）和通过改变环境条件（例如，突然的温度和盐度冲击）。 这项研究将大大提高识别Pfiesteria现场样品从鱼杀死/流行病，也将提高营养控制阶段的转换和丰富的两个已知物种的有毒Pfiesteria复杂的一般理解。

Recently, the potential for subtle but serious chronic/sublethal impacts from dino-flagellates known as the toxic Pfiesteria complex on fish health as well as human health was realized during toxic outbreaks in several tributaries of the largest estuary on the U.S. mainland, Chesapeake Bay. Much more massive fish kills and epizootics by Pfiesteria also had occurred in the second largest estuary, the Albemarle-Pamlico, for nearly a decade before the Chesapeake outbreaks. In the proposed research we will continue to examine trophic controls on the complex life cycles of Pfiesteria piscicida, and will extend similar effort to characterize the life cycle of a second toxic Pfiesteria-like species (not yet formally named) that recently was identified from the Neuse and Pocomoke Estuaries in the Albemarle-Pamlico Estuarine Ecosystem and Chesapeake Bay, respectively. Using advanced video imaging and motion analysis software, we will obtain full photographic documentation of the stage transformations in the complex life cycle of the two species of fish ambush-predators, through manipulation of available prey (algae, bacteria, shellfish, finfish, mammalian tissues) and through alteration of environmental conditions (e.g., sudden temperature and salinity shock). This research will greatly improve recognition of Pfiesteria in field samples from fish kills/epizootics, and will also enhance general understanding of trophic controls on stage transformations and abundance of both known species in the toxic Pfiesteria complex.