CAREER: Colonizing Land Via the Estuarine Route: Ontogeny of Osmoregulation and Settlement Behaviors in Three Brackish Water Fiddler Crabs

职业：通过河口路线殖民陆地：三种咸水招潮蟹的渗透调节和定居行为的个体发育

• 批准号: 0719600
• 负责人: Renae Brodie
• 金额: --
• 依托单位: Mount Holyoke College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-11-15 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0719600&HistoricalAwards=false
• 关键词: CAREER; Colonizing; Land; Via; Estuarine

CAREER: Colonizing land via the estuarine route: ontogeny of osmoregulation and settlement behaviors in three brackish water fiddler crabsRenae J. BrodieUniversity of South CarolinaThe colonization of land is one of the most significant evolutionary events in the history of animal life. While vertebrates are conspicuous members of terrestrial faunas, the most prolific and diverse land animals are actually invertebrates that have evolved from marine ancestors. One of the first challenges faced by colonizing marine invertebrates is the need to modify larval stages so they recruit near adult terrestrial habitats. Larval settlement behaviors must change and larvae must evolve the capability to tolerate physiological stresses that they encounter on land. In completely terrestrial animals, these early life stages develop on land within protective egg membranes or inside the adult parent. This study will examine changes in larval behavior and physiology in Uca minax, a freshwater fiddler crab that is at an intermediate stage of land invasion.To examine these changes, U. minax will be compared to two less terrestrial relatives, Uca pugilator and Uca pugnax. All three species undergo larval development in coastal marine waters. Using molecular genetic techniques, these fiddler crab species will be tracked from when they leave open coastal waters and enter South Carolina's north inlet estuary, until they join adult populations as juveniles. This will resolve the mystery of whether young crabs settle directly into adult habitats, move in gradually as they develop and grow, or settle randomly throughout the estuary, dying out in areas that are not suitable for them. Once patterns of settlement are established, larval responses to adult odor cues in different salinity environments will be investigated in the lab. A different suite of behavioral responses by U. minax compared to the other two species may help to explain how it invades adult freshwater and terrestrial habitats.To determine if young U. minax are physiologically adapted to survive low-salinity conditions, survivorship of larval and juvenile U. minax in a series of salinities (ocean-strength to freshwater) will be compared to that of U. pugilator, U. pugnax and U. uruguayensis, a distantly-related species from Brazil. Osmoregulatory ability (ability to control internal salt concentrations) at these salinities will also be assessed. In this way, it will be possible to explore the evolution of osmoregulatory changes in development that accompany the invasion of land in fiddler crabs.In addition to yielding evolutionary insights, this study will have ecological and educational impacts. Fiddler crabs are dominant players in southeastern estuaries, where they are important prey for birds and fishes, and modify landscape topography and species composition in areas where they burrow and feed. A more detailed understanding of the dispersal patterns, behavior and physiology of young fiddler crabs will facilitate the monitoring of estuaries. The educational benefits of this work will come from a strong effort to increase the level of participation of people of color in biological research. To this end, graduate and undergraduate students of color will be recruited from the University of South Carolina and nearby Historically Black Colleges and Universities to assist in the proposed research. Also, undergraduate and graduate students will turn aspects of the scientific work into hands-on activities for K-12 students that will be developed for a Web site about marine and terrestrial invertebrates with the assistance of local elementary-school children.

职业：通过河口路线殖民土地：三种半咸水招潮蟹的调节和定居行为的个体发生南卡罗来纳大学的Renae J. Brodie土地殖民是动物生命史上最重要的进化事件之一。虽然脊椎动物是陆地动物群的重要成员，但最多产和最多样化的陆地动物实际上是从海洋祖先进化而来的无脊椎动物。殖民海洋无脊椎动物面临的第一个挑战之一是需要修改幼虫阶段，以便它们在成年陆地栖息地附近招募。幼虫的定居行为必须改变，幼虫必须进化的能力，以容忍他们在陆地上遇到的生理压力。在完全陆生的动物中，这些早期生命阶段在陆地上的保护性卵膜内或成年父母体内发育。 这项研究将探讨在幼鱼的行为和生理的变化，在淡水招潮蟹，是在一个中间阶段的土地入侵。minax将与两个较少陆地的亲戚，Uca pugilator和Uca pugnax进行比较。所有这三个物种都在沿海沃茨经历幼虫发育。利用分子遗传技术，这些招潮蟹物种将被跟踪，从它们离开开放的沿海沃茨进入南卡罗来纳州的北入口河口，直到它们作为青少年加入成年种群。这将解决幼蟹是否直接定居在成年栖息地的谜团，随着它们的发育和生长逐渐移动，或者在整个河口随机定居，在不适合它们的地区灭绝。一旦建立了定居模式，将在实验室中研究幼虫对不同盐度环境中成虫气味线索的反应。 一套不同的行为反应，由美国。与其他两个物种的比较可能有助于解释它如何入侵成年淡水和陆地栖息地。在低盐环境下，幼鱼和幼鱼的存活率均较低。minax在一系列盐度（海洋强度淡水）将比较，美国。pugilator，U. pugnax和U. uruguayensis，一个来自巴西的远亲物种。还将评估这些盐度下的渗透调节能力（控制内部盐浓度的能力）。通过这种方式，将有可能探索伴随招潮蟹入侵土地的发育过程中的调节变化的演变。除了产生进化的见解外，这项研究还将产生生态和教育影响。招潮蟹是东南部河口的主导者，在那里它们是鸟类和鱼类的重要猎物，并在它们挖洞和觅食的地区改变景观地形和物种组成。对招潮蟹幼蟹的扩散模式、行为和生理的更详细的了解将有助于河口的监测。这项工作的教育效益将来自于为提高有色人种参与生物研究的水平所做的巨大努力。为此，将从南卡罗来纳州大学和附近的历史黑人学院和大学招募有色人种的研究生和本科生，以协助拟议的研究。此外，本科生和研究生将把科学工作的各个方面变成K-12学生的动手活动，这些活动将在当地小学生的帮助下为一个关于海洋和陆地无脊椎动物的网站开发。