Does mating success determine population growth rate at low abundance in marine copepods?

交配成功是否决定了海洋桡足类低丰度下的种群增长率？

• 批准号: 0351850
• 负责人: William Kimmerer
• 金额: --
• 依托单位: San Francisco State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0351850&HistoricalAwards=false
• 关键词: Does; mating; success; determine; population

Successful mating is a prerequisite for population growth in organisms that reproduce sexually. Unlike other determinants of population growth, mating success is inversely related to population density, resulting in an inverse density-dependent relationship between rate of increase and local population density. The resulting feedback should prevent dilute populations from persisting or growing; yet, they do persist. This project will examine the potential for poor mating success to suppress rate of increase of copepod populations at low density. This study will build on previous studies of mating in copepods that emphasized behavior and physiology; however, the focus of this research will be on consequences of behavior. That is, a series of experiments will support a model of the probability of successful mating as a function of local population density of adults. Copepods from an estuarine environment will be used under the expectation that they may be adapted to high density and therefore most likely to show effects at low density. The mating success probability model describes encounter rate, as in models describing feeding (Gerritsen 1980), together with simplified population dynamics. Although behavioral studies have determined volume search rates for mating, the conditional probability of actually mating upon encounter has not been determined. Model parameters include the product of the volume search rate and this conditional probability; this product, rather than its components, will be determined from experimental results. The experimental work will examine the frequency of mating in unmated copepods confined together under various conditions of density, sex ratio, container size, and food concentration. These experiments will be conducted using copepods of various species with a range of swimming and searching behaviors in an attempt to determine how these behaviors result in different mating frequencies. Preliminary and ancillary experiments will test for experimental artifacts and issues such as time for males to regenerate sperm after mating. Environmental determinants of copepod sex ratio, a key parameter in mating probability, will also be examined with an emphasis on the potential role of dietary lipids. Intellectual merit: Zooplankton occupy a key role in oceanic foodwebs, and their population dynamics has been the subject of considerable research. Among determinants of population growth rate, mating success has received relatively little study, and most of that has been on behavior and anatomical structure. Yet, mating success should be a key determinant of recovery of populations from periods of low abundance, as well as establishment of new populations from initial seeds. This research builds on previous work to include all components of mating (Buskey 1998) rather than only encounter rate. Broader impacts: The results of this research will have impacts in two areas important to society. First, invasive species, a major concern in coastal waters, must establish populations from initially small inocula, which are therefore subject to the positive feedback addressed here. Second, these results may be transferable, at least in principle, to the study of endangered and rare species of other taxonomic groups. The proposed research will also contribute to education by providing an opportunity for a Master's thesis at San Francisco State University, a minority-serving institution.

成功的交配是有性繁殖生物种群增长的先决条件。 与其他决定种群增长的因素不同，交配成功率与种群密度呈负相关，导致种群增长率与当地种群密度之间呈负相关关系。 由此产生的反馈应该阻止稀释种群的持续或增长;然而，它们确实持续存在。本计画将探讨低密度下交配成功率不佳对抑制桡足类种群增长率的可能性。 这项研究将建立在以前的研究交配桡足类，强调行为和生理，然而，这项研究的重点将是行为的后果。 也就是说，一系列的实验将支持一个模型的成功交配的概率作为当地人口密度的成年人。 将使用来自河口环境的桡足类，因为预期它们可能适应高密度，因此最有可能在低密度下显示效果。 交配成功概率模型描述了相遇率，就像描述进食的模型一样（Gerritsen 1980），以及简化的种群动态。 虽然行为研究已经确定了大量的搜索率交配，条件概率实际上交配后遇到尚未确定。 模型参数包括体积搜索率和该条件概率的乘积;将根据实验结果确定该乘积，而不是其组成部分。 实验工作将研究在不同的密度，性别比例，容器大小和食物浓度条件下，未交配的桡足类限制在一起的交配频率。 这些实验将使用具有一系列游泳和搜索行为的各种桡足类进行，试图确定这些行为如何导致不同的交配频率。 初步和辅助实验将测试实验文物和问题，如男性交配后再生精子的时间。 桡足类性别比的环境决定因素，交配概率的一个关键参数，也将审查强调饮食脂质的潜在作用。智力优势：浮游动物在海洋食物网中发挥着关键作用，其种群动态一直是大量研究的主题。 在种群增长率的决定因素中，交配成功的研究相对较少，大部分研究都是关于行为和解剖结构的。 然而，交配成功应该是从低丰度时期恢复种群的关键决定因素，以及从最初的种子建立新的种群。 这项研究建立在以前的工作，包括交配的所有组成部分（Buskey 1998），而不仅仅是遇到率。更广泛的影响：这项研究的结果将对社会重要的两个领域产生影响。 首先，入侵物种，在沿海沃茨的一个主要问题，必须建立从最初的小接种种群，因此受到这里讨论的积极反馈。 其次，这些结果至少在原则上可以转移到其他分类群的濒危和稀有物种的研究中。 拟议中的研究还将通过提供在为少数民族服务的机构旧金山弗朗西斯科州立大学撰写硕士论文的机会，为教育做出贡献。