Further Investigations on Larval Nutrition and its Influence on Juvenile Performance of Benthic Invertebrates: Competition, Thermal Stress, and Natural Populations

幼虫营养及其对底栖无脊椎动物幼体表现的影响的进一步研究：竞争、热应激和自然种群

• 批准号: 9911682
• 负责人: Richard Emlet
• 金额: $ 30万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9911682&HistoricalAwards=false
• 关键词: Further; Investigations; Larval; Nutrition; its

The nutritional condition of benthic invertebrate larvae and its potential influence on juvenile performance (growth and survival in the days and weeks after settlement) is an almost unstudied area of marine ecology. Further understanding of the connections between oceanic (planktonic) and benthic components of the complex life-cycles of many marine invertebrates will require exploration of how the nutritional environment of the planktonic larva affects the performance of the post-metamorphic, benthic juvenile. In the first 3 years of work on this topic, we have shown that larval diet, manipulated in the laboratory, resulted in changes in larval organic content and size. Furthermore manipulations of larval diet had significant influences on growth and survival of newly metamorphosed/batched benthic juveniles under field conditions. This research joined lab experiments and field studies on juveniles from three different invertebrate phyla (barnacles, sea urchins and snails) and should help focus attention on early juvenile biology of marine invertebrates. Increased understanding of early juveniles should help clarify the importance of larval supply and post-settlement processes in population dynamics such as structuring populations and marine communities. It may also reveal whether larval nutritional status affects survival of juveniles to adulthood.In the proposed research, investigations will determine how variations in larval nutritional history may affect intraspecific and interspecific competitive interactions among young juveniles. A number of different barnacle species that occur in intertidal and subtidal habitats in coastal and estuarine environments will be studied, thereby exploring influences of larval nutrition in habitats that vary in types and degrees of stresses (temperature, desiccation, and salinity, and types of food). Competitive interactions among juvenile and adult barnacles are well documented, but whether larval nutritional history has an influence on competitive outcome is unknown. By placing juveniles in interactive situations, this work will explore the influence of larval nutrition in field conditions that reflect settlement conditions in natural populations of many species.A second part of the work will examine how larval nutritional history effects other features of juveniles besides their growth and survival. Measurements will be made on the effects of larval nutritional on the size of the juvenile feeding apparatus and molt rate and on the biochemical response of juveniles to thermal stress. This data will show morphological and physiological consequences of larval diet and contribute to our understanding of why growth and survival are affected. For the physiological responses to thermal stress, the induction of heat shock proteins (lisp 70's & 90's) and ubiquitin-conjugates will be quantified, (proteins that reflect reversible and irreversible damage to proteins, respectively).Lastly, examinations of natural variation will be made for larval size and energy content and its affects on juvenile performance of the same barnacles for which we have conducted experimental manipulations, competition studies and physiological studies. By measuring size at metamorphosis and following performance of naturally settling barnacles we can determine whether the manipulations created in the laboratory are reflected among natural populations. Additional measures of larval size, organic content, and expression of thermal stress proteins will help join the laboratory and field-based studies. Natural settlement will be monitored throughout the year to look for seasonal patterns in larval quality and whether larval quality consistently influences juvenile performance.This project should provide much needed empirical data on juvenile growth and survival, a broader context for understanding the role of larval nutrition, and new methodologies for further experimental investigations of juvenile ecology of marine invertebrates.

底栖无脊椎动物幼体的营养状况及其对幼体表现（定居后数天和数周内的生长和存活）的潜在影响几乎是海洋生态学中未研究的领域。要进一步了解许多海洋无脊椎动物复杂生命周期的海洋（浮游）和底栖组成部分之间的联系，就需要探索浮游幼虫的营养环境如何影响变质后底栖幼鱼的表现。在第一个3年的工作就这一主题，我们已经表明，幼虫的饮食，在实验室中操作，导致幼虫的有机含量和大小的变化。此外，操纵幼虫的饮食有显着的影响，在现场条件下的生长和生存的新变态/分批底栖幼鱼。这项研究结合了实验室实验和对三种不同无脊椎动物门（藤壶，海胆和蜗牛）幼鱼的实地研究，应该有助于关注海洋无脊椎动物的早期幼鱼生物学。增加对早期青少年的了解，应有助于澄清幼虫供应和定居后的人口动态过程，如结构人口和海洋社区的重要性。这也可能揭示幼虫的营养状况是否会影响幼体的生存到adulth.In拟议的研究中，调查将确定幼虫的营养历史的变化可能会影响种内和种间竞争的相互作用之间的年轻的少年。一些不同的藤壶物种发生在潮间带和潮下带的栖息地在沿海和河口环境将进行研究，从而探索不同类型和程度的应力（温度，干燥，盐度和食物类型）的栖息地幼虫营养的影响。少年和成年藤壶之间的竞争相互作用是有据可查的，但幼虫的营养历史是否有竞争结果的影响是未知的。本研究通过将幼鱼置于互动的环境中，探讨了在反映许多物种自然种群定居条件的野外条件下，幼鱼营养对幼鱼的影响。将测量幼虫营养对幼鱼摄食器大小和蜕皮率的影响以及幼鱼对热应激的生化反应。这些数据将显示幼虫饮食的形态和生理后果，并有助于我们理解为什么生长和生存受到影响。对于热应激的生理反应，热休克蛋白（lisp 70's 90's）和泛素缀合物的诱导将被量化，（分别反映可逆和不可逆损伤的蛋白质）。最后，将对幼虫大小和能量含量的自然变异及其对相同藤壶的幼年表现的影响进行检查，我们已经进行了实验操作，竞争研究和生理研究。通过测量变形的大小和自然沉降的藤壶的性能，我们可以确定在实验室中创建的操作是否反映在自然种群中。幼虫大小，有机物含量和热应激蛋白表达的其他措施将有助于加入实验室和实地研究。将全年监测自然沉降，以寻找幼虫质量的季节性模式，以及幼虫质量是否持续影响幼鱼的表现。该项目应提供急需的幼鱼生长和存活的经验数据，为理解幼鱼营养的作用提供更广泛的背景，并为进一步实验研究海洋无脊椎动物幼鱼生态学提供新的方法。