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: 0237484
• 负责人: Renae Brodie
• 金额: $ 57.43万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0237484&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：通过河口途径殖民土地：在三个微钻水的水提琴手螃蟹中的渗透调节和定居行为的个体，南卡罗来纳州土地上的殖民化是动物生活史上最重要的进化事件之一。尽管脊椎动物是陆地动物群的显着成员，但最多产，多样的陆地动物实际上是从海洋祖先演变而来的无脊椎动物。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，因此他们在成人陆地栖息地附近招募。幼虫定居行为必须改变，幼虫必须发展能够忍受其在陆地上遇到的生理压力的能力。在完全的陆地动物中，这些早期生命阶段在保护性卵膜内或成年父母内部发展。 这项研究将研究UCA Minax的幼体行为和生理变化，UCA Minax是一种处于土地侵袭的中间阶段的淡水提琴手蟹。要检查这些变化，U。Minax将与两个较少的陆地亲属，UCA Pugilator和UCA Pugnax进行比较。这三种物种在沿海海水中都经历了幼体发育。使用分子遗传技术，这些提琴手螃蟹物种将从开放的沿海水域并进入南卡罗来纳州的北进口河口时进行追踪，直到它们以成年人的身份加入成年人。这将解决年轻螃蟹是否直接定居在成年栖息地中，随着它们的发展和生长的逐渐移动，还是在整个河口中随机定居，在不适合他们的地区垂死。一旦建立了沉降模式，将在实验室中研究不同盐度环境中成人气味线索的幼体反应。 与其他两个物种相比，U. Minax的一系列行为反应可能有助于解释它如何侵入成人的淡水和陆地栖息地。确定年轻的U. Minax是否在生理上适应了在幼体和U. Minax的低含量条件下生存的幼虫和少年Minax在一系列盐度（Ocean-stretities to poug pug and pug pug and pugilator and pugilator and poug and pugil and pugil and pugil for pougil and，乌拉圭，这是一种与巴西的远距离相关物种。还将评估渗透调节能力（控制内部盐浓度的能力），也将评估。通过这种方式，可以探索在提琴手螃蟹中入侵土地的发育变化的演变。除了产生进化见解外，这项研究还将产生生态和教育的影响。提琴手螃蟹是东南河口的主要参与者，在那里它们是鸟类和鱼类的重要猎物，并在它们挖洞和喂食的地区修改了景观地形和物种组成。对年轻提琴手螃蟹的分散模式，行为和生理学的更详细理解将有助于监测河口。这项工作的教育益处将源于提高有色人种在生物学研究中的参与程度的巨大努力。为此，将从南卡罗来纳大学和附近历史上黑人大学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转变为K-12学生的动手活动，这些活动将在当地小学儿童的帮助下为有关海洋和陆地无脊椎动物的网站开发。