CREST-PRF: Linking physiology and demography in the Eastern Mosquitofish Gambusia holbrooki

科学与技术卓越研究中心博士后研究奖学金（CREST- prf）项目支持具有重大潜力的CREST中心研究人员，并为他们提供培训和研究经验，以拓宽视野，促进跨学科互动，并使他们在科学界处于领导地位。该CREST- prf项目与佛罗里达国际大学CREST水生化学与环境中心（CAChE）的研究重点相一致。该项目将重点关注汞（Hg）如何影响生物体的生理、生命率和当地人口增长。Everglades是一个相互连接的淡水生态系统网络，包括受汞及其甲基化或有机形式甲基汞污染的当地地区，将为这项研究提供一个天然实验室。东方蚊鱼Gambusia holbrooki将被用作模型物种，以记录由水污染物（汞）引起的生理应激对人口和种群的影响。由于东部食蚊鱼在大沼泽地的食物网中起着至关重要的作用，这个项目将提高我们对人为污染物如何影响水生生物群的认识和理解。本研究结果将有助于设计保护和恢复活动。这项研究将有助于培养一名拉丁美洲学生的博士后，从而增加在STEM领域寻求职业发展的少数族裔候选人的数量，这是CREST-CAChE的一个重要目标。此外，该研究项目将纳入中心的教育和外展计划。这项研究的首要目标是确定生物体对环境压力的生理反应是否会调节个体和群体的表现。尽管其他研究已经调查了水生生物中应激的人口统计学后果，但考虑多种生活史特征（如生长、生存和繁殖）的研究很少。此外，有必要研究由于生理压力导致的资源分配模式的变化如何影响当地种群动态。本研究还将通过测量生物生理条件与人口和种群表现之间的关系，检验生活史权衡假设作为理解物种适应环境条件的基础。该项目将通过实地和受控实验室实验测量G. holbrooki对汞引起的生理应激的人口反应来解决这些差距。人口统计数据（生长、生存和生殖产出）将用于开发基于阶段的人口矩阵模型，以估计不同生理压力下的人口增长率。通过将经验生理学数据与人口统计学模型相结合，提出的研究将是第一个直接测试这种关系的研究。这项研究的结果将为使用生理测量作为生物标志物来确定水污染物对水生生物的人口统计学和生活史特征的影响的成功（或失败）提供定量证据。

The Centers of Research Excellence in Science and Technology-Postdoctoral Research Fellowship (CREST-PRF) track within the CREST program supports beginning CREST Center investigators with significant potential and provides them with training and research experiences that will broaden perspectives, facilitate interdisciplinary interactions and establish them in positions of leadership within the scientific community. This CREST-PRF project is aligned with the research focus of the CREST Center for Aquatic Chemistry and the Environment (CAChE) at Florida International University. The project will focus on how mercury (Hg) affects organisms' physiology, vital rates, and local population growth. The Everglades, a network of interconnected freshwater ecosystems that includes local areas contaminated by (Hg) and its methylated or organic form, methylmercury, will provide a natural laboratory for this study. The eastern mosquitofish, Gambusia holbrooki, will be used as a model species to document the demographic and population consequences of physiological stress induced by water contaminants (Hg). Since the eastern mosquitofish play a critical role in the Everglades food webs, this project will advance our knowledge and understanding of how human-induced contaminants affect aquatic biota. Findings from this study will be useful for designing conservation and restoration activities. The research will contribute to the postdoctoral training of a Latin American student, thus increasing the number of underrepresented minority candidates pursuing a career in STEM, an important goal of the CREST-CAChE. In addition, this research project will be integrated into the education and outreach program at the Center.The overarching goal of the research is to determine whether the organism's physiological response to environmental stress regulates individual and population performance. Although other studies have examined the demographic consequences of stress in aquatic organisms, studies considering multiple life-history traits (e.g. growth, survival, and reproduction) are scarce. Furthermore, research examining how local population dynamics are affected by variation in patterns of resource allocation due to physiological stress, are warranted. This study will also test the life-history trade-off hypothesis as the basis to understand species' adaptation to environmental conditions by measuring the relationship between organisms' physiological conditions and demographic and population performance. This project will address such gaps by measuring, both in the field and in controlled lab experiments, the demographic response of G. holbrooki to mercury-induced physiological stress. The demographic data (growth, survival, and reproductive output) will be used to develop stage-based population matrix models to estimate population growth rates under different physiological pressures. By combining empirical physiological data with demographic modeling, the proposed study will be among the first to test such a relationship directly. The outcomes of this study will provide quantitative evidence of the success (or failure) of using physiological measurements as a biomarker to determine the effects of water contaminants in the demography and life-history traits of aquatic organisms.