Collaborative Research: Relevance of Planktonic Larval Dispersal to Endemism and Biogeography of Antarctic Benthic Invertebrates

合作研究：浮游幼虫扩散与南极底栖无脊椎动物特有现象和生物地理学的相关性

• 批准号: 0338087
• 负责人: Rudolf Scheltema
• 金额: --
• 依托单位: Woods Hole Oceanographic Institution
• 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: 2004-02-15 至 2010-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0338087&HistoricalAwards=false
• 关键词: Collaborative; Research; Relevance; Planktonic; Larval

Because of extreme isolation of the Antarctic continent since the Early Oligocene, one expects a unique invertebrate benthic fauna with a high degree of endemism. Yet some invertebrate taxa that constitute important ecological components of sedimentary benthic communities include more than 40 percent non-endemic species (e.g., benthic polychaetes). To account for non-endemic species, intermittent genetic exchange must occur between Antarctic and other (e.g. South American) populations. The most likely mechanism for such gene flow, at least for in-faunal and mobile macrobenthos, is dispersal of planktonic larvae across the sub- Antarctic and Antarctic polar fronts. To test for larval dispersal as a mechanism of maintaining genetic continuity across polar fronts, the scientists propose to (1) take plankton samples along transects across Drake passage during both the austral summer and winter seasons while concurrently collecting the appropriate hydrographic data. Such data will help elucidate the hydrographic mechanisms that allow dispersal across Drake Passage. Using a molecular phylogenetic approach, they will (2) compare seemingly identical adult forms from Antarctic and South America continents to identify genetic breaks, historical gene flow, and control for the presence of cryptic species. (3) Similar molecular tools will be used to relate planktonic larvae to their adult forms. Through this procedure, they propose to link the larval forms respectively to their Antarctic or South America origins. The proposed work builds on previous research that provides the basis for this effort to develop a synthetic understanding of historical gene flow and present day dispersal mechanism in South American/Drake Passage/Antarctic Peninsular region. Furthermore, this work represents one of the first attempts to examine recent gene flow in Antarctic benthic invertebrates. Graduate students and a postdoctoral fellow will be trained during this research.

由于南极大陆自早渐新世以来的极端孤立，人们期望具有高度特有性的独特无脊椎底栖动物群。然而，一些构成沉积底栖生物群落重要生态组成部分的无脊椎动物类群包括40%以上的非特有物种（例如，底栖多毛类）。为了解释非特有物种，南极和其他（如南美）种群之间必须发生间歇性的遗传交换。这种基因流动最可能的机制，至少对于动物群内和移动的大型底栖动物来说，是浮游幼虫跨越亚南极和南极极地锋的扩散。为了测试幼虫扩散作为维持极地前沿遗传连续性的机制，科学家们建议（1）在南方夏季和冬季沿德雷克海峡的沿着断面采集浮游生物样本，同时收集适当的水文数据。这些数据将有助于阐明水文机制，使整个德雷克海峡扩散。使用分子系统发育方法，他们将（2）比较来自南极和南美洲大陆的看似相同的成年形式，以确定遗传断裂，历史基因流，并控制神秘物种的存在。(3)类似的分子工具将被用于将寄生幼虫与它们的成虫形式联系起来。通过这一程序，他们建议将幼虫形式分别与它们的南极或南美洲起源联系起来。拟议的工作建立在以前的研究，提供了基础，这一努力发展的历史基因流和现今的传播机制在南美/德雷克海峡/南极半岛地区的综合理解。此外，这项工作是首次尝试研究南极底栖无脊椎动物最近的基因流之一。研究生和博士后研究员将在本研究期间接受培训。