Trophic Interactions of Ambush Predator Dinoflagellates in Estuarine Microbial Food Webs

河口微生物食物网中伏击捕食者甲藻的营养相互作用

• 批准号: 9403920
• 负责人: JoAnn Burkholder
• 金额: $ 40万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-15 至 1998-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9403920&HistoricalAwards=false
• 关键词: Trophic; Interactions; Ambush; Predator; Dinoflagellates

BURKHOLDER 9403920 The diverse heterotrophic dinoflagellates include free- living estuarine species that demonstrate "ambush predator" behavior toward algal, protozoan, or fish prey. This behavioral pattern is widespread; thus far, it has been reported from the Mediterranean Sea, the Gulf of Mexico, and the western Atlantic. Within the past two years, a new genus of ambush predator dinoflagellate, Pfiesteria (nov. gen.) has been discovered, with known species having a complex life cycle that includes at least 15 stages. Among these stages are persistent amoeboid heterotrophs and ephemeral "phantom-like" flagellates that are common in eutrophic mid-Atlantic and Gulf Coast estuaries, and likely are widespread throughout warm temperate and subtropical waters. The ubiquitous occurrence and abundance of these stages in the water column and sediments, their voracious phagotrophy on bacterial, algal, and microfaunal prey, and their lethality to fish point to a major role of ambush predator dinoflagellates in the structure and function of estuarine food webs. This project is to experimentally examine the nutritional ecology and trophic interactions of abundant stages of Pfiesteria piscimorte (nov. gen. et sp.) as a representative toxic ambush predator, toward determining the role of these organisms -- in their many forms -- within estuarine food webs. This project will: (1) examine saprotrophic nutrition of the biflagellate and amoeboid forms on stimulatory secretions of finfish prey; (2) characterize phagotrophic interactions between Pfiesteria (nov. gen.) and bacterial, algal and microfaunal prey; and (3) determine the influence of the biflagellate and amoeboid stages on representative microbial predators. The insights gained from this research will alter general paradigms about the role of dinoflagellates in the structure and function of food webs n eutrophic warm temperate estuaries.

伯克霍尔德9403920 不同的异养甲藻包括自由生活的河口物种，表现出“伏击捕食者”的行为对藻类，原生动物，或鱼类的猎物。 这种行为模式是广泛的;到目前为止，它已报告从地中海，墨西哥湾和西大西洋。 在过去的两年中，伏击捕食性甲藻的一个新属，Pfiesteria（nov. gen.）已知的物种有一个复杂的生命周期，包括至少15个阶段。 在这些阶段中，持久的变形虫异养生物和短暂的“幻影状”鞭毛虫是常见的富营养化大西洋中部和墨西哥湾沿岸河口，并可能广泛分布在整个暖温带和亚热带沃茨。 无处不在的发生和丰富的这些阶段的水柱和沉积物中，他们贪婪的噬菌性的细菌，藻类和微型动物的猎物，其致命性鱼类点伏击捕食者腰鞭毛虫在河口食物网的结构和功能的一个重要作用。 本研究旨在通过实验研究鱼腥藻Pfiesteria piscimorte（nov.gen.et sp.） 作为一个代表性的有毒伏击捕食者，对确定这些生物的作用-在他们的许多形式-在河口食物网。 该项目将：（1）研究了双鞭藻和变形虫两种形态对鱼类猎物刺激性分泌物的腐营养作用;和细菌，藻类和微型动物的猎物;和（3）确定的双鞭毛虫和变形虫阶段的代表性微生物捕食者的影响。 从这项研究中获得的见解将改变一般范式的甲藻的结构和功能的食物网N富营养化暖温带河口的作用。