RUI: Effects of large inedible particles on larval feeding, planktonic larval duration, and juvenile quality in marine invertebrates

许多具有重要生态和经济意义的海洋无脊椎动物（如牡蛎、螃蟹和海胆）的生命周期包括摄食幼虫阶段，幼虫阶段作为浮游生物的一部分生活在水中。这些幼虫花几天或几周的时间以微小的藻类颗粒为食，以促进它们的发育，直到它们能蜕变成幼鱼。然而，在自然界中，浮游生物不仅包括可食用的颗粒，还包括许多大到不能吃的颗粒，这些颗粒可能会干扰对可食用颗粒的捕食。这些包括，例如，大的藻类颗粒，其他无脊椎动物的卵和胚胎，再悬浮的沉积物，以及人为的纳米和微塑料。当幼虫遇到不可食用的大颗粒时，它们可能会通过改变游泳行为来避开它们，或者通过捕获然后拒绝它们。这种相互作用降低了幼虫捕获可食用颗粒的速度，这迫使它们要么在变形前花更多的时间进食（增加了它们被浮游生物捕食者杀死的总体风险），要么用更少的能量变形，在相对较差的条件下产生幼鱼。该项目研究了大型不可食用颗粒如何影响各种海洋无脊椎动物幼虫的摄食，变态时间和幼崽状况。该项目有可能极大地改变我们对幼虫如何在自然群落中觅食和生存的理解，从而改变我们对这些重要生物种群动态的理解。该项目将为加州州立大学长滩分校（California State University Long Beach）的本科生和研究生提供研究培训机会，并为当地两所社区学院的学生提供暑期研究实习机会。项目数据将被整合到本科课程的实验模块中。最后，加州各种海洋无脊椎动物的生殖生物学数据将被添加到一个公共网站上，供公众、学生和对这些普通动物的发育、生活史、生态学和进化感兴趣的生物学家广泛使用。控制海洋无脊椎动物浮游持续时间和幼体状况的因素长期以来被认为是了解其生态学和进化的关键因素。幼虫的饲养环境显然是其中一个因素，但之前的工作几乎只关注环境的一个特征，即食物的丰富性。这个项目将评估幼虫摄食环境的另一个潜在的关键维度的重要性。浮游生物：在自然浮游生物群落中大量存在的不可食用的大颗粒它采用比较的方法来解决两个关键问题，即大型不可食用颗粒对幼虫（包括棘皮动物、环节动物和软体动物的幼虫）的影响，这些幼虫使用几种不同的颗粒捕获机制进食。首先，天然浮游生物中存在的不可食用的大颗粒是否会降低幼虫的取食率？其次，大的不可食用颗粒的存在是否延长了幼虫浮游生物的持续时间或导致生产质量较低的幼鱼？幼虫的摄食率将在短期实验中测量，在实验中，幼虫暴露于食物和在一定浓度范围内的天然或人工大的不可食用颗粒。大型不可食用颗粒对浮游生物持续时间和幼鱼质量的影响将通过在不同浓度的大型不可食用颗粒中培养幼虫的整个生命周期来测量。由于摄食性能是浮游生物持续时间、幼虫存活率和幼鱼状况的重要决定因素，该项目将大大增加我们对浮游生物状况如何影响许多以幼虫为食的海洋无脊椎动物种群动态的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Many ecologically and economically important marine invertebrates (e.g., oysters, crabs, and sea urchins) have life cycles that include feeding larval stages that live drifting in the water as part of the plankton. These larvae spend days or weeks feeding on tiny algal particles to fuel their development until they can metamorphose into juveniles. In nature, however, the plankton includes not only edible particles, but also many particles that are too large to be eaten but which may interfere with feeding on edible particles. These include, for example, large algal particles, eggs and embryos of other invertebrates, re-suspended sediment, and anthropogenic nano- and micro-plastics. When larvae encounter large inedible particles, they may respond by altering their swimming behavior to avoid them, or by capturing and then rejecting them. Such interactions reduce the rate at which larvae can capture edible particles, which forces them to either spend more time feeding before metamorphosis (increasing their overall risk of dying due to planktonic predators), or to metamorphose with less energy, producing juveniles in relatively poor condition. This project examines how large inedible particles affect feeding, time to metamorphosis, and juvenile condition in the larvae of diverse marine invertebrates. The project has the potential to dramatically change our understanding of how larvae feed and survive in natural communities, and thus our understanding of the population dynamics of these important organisms. The project will support research training opportunities for undergraduate and graduate students at California State University Long Beach, a primarily undergraduate institution, as well as summer research internships for students at two local community colleges. Project data will be integrated into laboratory modules in undergraduate courses. Finally, data on the reproductive biology of diverse California marine invertebrates will be added to a public website that is widely used by members of the public, students, and biologists interested in the development, life histories, ecology, and evolution of these common animals. The factors that control planktonic duration and juvenile condition in marine invertebrates with feeding larvae have long been recognized as critical to understanding their ecology and evolution. Larval feeding environment is clearly one of those factors, but previous work has focused almost exclusively on one feature of that environment, the abundance of food. This project will evaluate the importance of another potentially critical dimension of the larval feeding environment ? the presence of large inedible particles, which are frequently abundant in natural plankonic communities. It takes a comparative approach to address two key questions about the effects of large inedible particles on larvae (including those of echinoderms, annelids, and molluscs) that feed using several different particle capture mechanisms. First, do large inedible particles present in natural plankton reduce larval feeding rates? And second, does the presence of large inedible particles extend larval planktonic duration or result in the production of lower quality juveniles? Feeding rates of larvae will be measured in short-term experiments in which larvae are exposed to both food and to natural or artificial large inedible particles over a range of concentrations. Effects of large inedible particles on planktonic duration and juvenile quality will be measured by culturing larvae through their entire life cycles in the presence of large inedible particles at various concentrations. Because feeding performance is an important determinant of planktonic duration, larval survival, and juvenile condition, the project will add greatly to our understanding of how conditions in the plankton affect the population dynamics of the many marine invertebrates with feeding larvae.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.