Collaborative Research: The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula

合作研究：南极半岛浅水海洋大型藻类和无脊椎动物的化学生态学

• 批准号: 0442769
• 负责人: James McClintock
• 金额: $ 40.5万
• 依托单位: University of Alabama at Birmingham
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-15 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0442769&HistoricalAwards=false
• 关键词: Collaborative; Research; Chemical; Ecology; Shallow

Mesoherbivores, and specifically amphipods, are a conspicuous and dominant component of the macroalgal community in Antarctica. Despite their high abundance, the functional ecology, and particularly the trophic relationships of Antarctic amphipods are poorly understood. This project will evaluate the importance of mesograzers (small invertebrate predators approximately 1 to 25 mm in body length) in western Antarctic Peninsula marine communities. This will be accomplished by examining the role of mesoherbivores in structuring macroalgal communities and by elucidating the ecological interactions of mesograzers with a dominant group of benthic macroinvertebrates, the marine sponges. Moreover, chemical studies will be conducted to gain a more thorough understanding of the chemical defenses that Antarctic Peninsula sponges direct towards crustacean mesograzers. Three sets of questions will be addressed concerning the importance of mesograzers, and amphipods in particular, in nearshore habitats of the western Antarctic Peninsula. First, the hypothesis that mesoherbivory is particularly heavy in western Antarctic Peninsula marine communities and has an important influence on algal community structure will be addressed. Initial studies will document which species of amphipods feed in whole or part on microalgae and macroalgae, the incidence and distribution of filamentous endophytes in dominant macroalgae, comparative night time patterns of amphipod abundances on macrophytes, and the role of chemical mediation in these relationships. Second, the broad hypothesis that mesograzers in general, and amphipods in particular, interact with and prey upon sponges to a greater extent than heretofore recognized in Antarctic communities will be tested. The functional basis of these associations will be considered by examining whether the sponges are used as prey, and if so, whether there is evidence that some sponges produce secondary metabolites that show efficacy against mesograzers such as amphipods. Third, the researchers will test the hypotheses that: 1) Antarctic algae and invertebrates biosynthesize secondary metabolites that deter feeding by amphipod predators; and 2) pigments found in three Antarctic sponges are tryptophan catabolites produced as defenses against crustacean predators that impact molting. Evaluation of these hypotheses will be based on isolation and characterization of the specific anti-feeding metabolites, on biosynthetic studies to establish the metabolic origin of the pigments, and on bioassays to establish the chemical defense roles of both groups of compounds. A variety of educational activities will be a major component of this project. Opportunities will be made to support graduate and undergraduate research, both through NSF programs as well as home university-based programs including a number of funded programs that enhance the representation of minorities in the sciences. Through their proven and highly successful interactive web program, the investigators will continue to involve a large numbers of teachers, K-12 students, and other members of the community at large in their scientific endeavors in Antarctica. Moreover, they will actively participate in outreach efforts by presenting numerous talks on their research to school and community groups.

中植物，特别是两亲脚架，是南极大藻社区的显着组成部分。 尽管它们的丰度很高，但功能性生态学，尤其是南极两亲脚的营养关系知之甚少。 该项目将评估南极西部半岛海洋群落中中杂种剂（小无脊椎动物捕食者的体长约1至25毫米）的重要性。这将通过检查中植菌在构建大型藻类群落中的作用，并阐明中综合体与主要底栖大型无脊椎动物（海洋海绵）的生态相互作用。 此外，将进行化学研究，以更透彻地了解南极半岛海绵直接朝着甲壳类中心的杂物。将解决三组问题，以了解中摩龙的重要性，尤其是在南极半岛近岸栖息地的两亲动物的重要性。 首先，将解决中南极半岛海洋社区中介质小菜的假设尤为严重，并且将对藻类社区结构产生重要影响。 最初的研究将记录哪种两亲脚的物种全部或部分以微藻和大量藻类为食，在主要的大藻类中的丝状内生菌的发生率和分布，大型植物上的Amphipod丰度的比较夜间模式以及化学介导在这些关系中的作用。 其次，广泛的假设是，尤其是中果植物，尤其是两栖动物，与海绵相互作用和猎物的相互作用比在南极社区中所认识到的更大程度要大。 这些关联的功能基础将通过检查是否将海绵用作猎物来考虑，如果是这样，是否有证据表明某些海绵产生了二级代谢产物，这些代谢物表现出针对诸如Amphipods之类的中摩龙的功效。 第三，研究人员将检验以下假设：1）南极藻类和无脊椎动物生物合成的次生代谢产物，这些代谢产生了两栖动物捕食者的进食； 2）在三个南极海绵中发现的颜料是色氨酸分解代谢物，作为对影响摩擦的甲壳类动物的防御性。 对这些假设的评估将基于特定抗喂养代谢物的分离和表征，生物合成研究以确定颜料的代谢起源，以及在生物测定中建立两种化合物的化学防御作用。各种教育活动将是该项目的主要组成部分。通过NSF计划以及基于家庭大学的计划，包括许多资助的计划，可以帮助研究生和本科研究，以增强科学中少数群体的代表。通过其经过验证的非常成功的互动网络计划，调查人员将继续涉及大量的教师，K-12学生和整个社区的其他成员在南极的科学努力中。 此外，他们将通过向学校和社区团体进行许多关于研究的演讲，积极参与外展工作。