The Role of Prey Capture Thread in the Origin and Evolution of Spider Orb-webs

9417803蜘蛛在使用圆网捕捉猎物方面是独一无二的。球状编织蜘蛛和它们的网引起了研究行为、生态学和进化的生物学家的注意，也引起了生物化学家和分子生物学家的兴趣，他们研究蜘蛛制造的丝的特性来构建这些网。一张圆网捕获猎物的能力在很大程度上取决于猎物捕获线的粘性。如果没有这些线，许多击网的昆虫就会在蜘蛛跑到并制服它们之前逃脱。猎物捕获线还有助于吸收攻击网络的猎物的影响，并通过这种方式加强网络。然而，这些猎物捕获线的特性得到的研究很少。这项研究将研究猎物捕获线的特性变化，并确定它们如何与蜘蛛球网的起源、进化和运行相关联。最原始的球网是水平定向的，含有干燥的、模糊的捕获线，称为甲缘线。更先进和多样化的球状编织蜘蛛群体产生垂直方向的球状蛛网，其中包含粘性粘性捕获线。这项研究将测量猎物从组织不如球网、含有筛线的球网和含有粘合线的球网捕获的线的粘性、抗拉强度和延展性。这项研究将检验这样的假设，即精确而节俭的圆网结构非常重视捕获线的粘性、抗拉强度和延伸性；这些特征在垂直圆网中变得更加关键，因为垂直圆网的定向需要它们吸收更大的力，因为它们拦截飞行更快的猎物。它还将展示脑部猎物捕捉线的粘性如何与蜘蛛的旋转解剖有关，并确定旋转解剖的变化是否促进了球网的起源。从这一比较中获得的信息和见解将回答关于蜘蛛网进化的主要问题，更全面地表征蜘蛛丝的功能特性，并促进对蜘蛛网的组成、结构和功能的更全面的看法。这些见解最终可能在复合材料和粘结剂或冲击吸收结构的设计中有用。

9417803 Spiders are unique in their use of orb-webs to capture prey. Orb-weaving spiders and their webs have attracted the attention of biologists who study behavior, ecology, and evolution as well as the interest of biochemists and molecular biologists who study the properties of the silk spiders manufacture to build those webs. The ability of an orb-web to capture prey depends in large part on the stickiness of its prey capture threads. Without these threads, many insects that strike a web would escape before a spider could run to and subdue them. Prey capture threads also help absorb the impact of prey that strike a web and, in this way, strengthen the web. The properties of these prey capture threads, however, have received very little study. This research will examine changes in the properties of prey capture threads and determine how they are associated with the origin, evolution, and operation of spider orb-webs. The most primitive orb-webs are horizontally oriented and contained dry, fuzzy capture threads called cribellar thread. More advanced and diverse groups of orb-weaving spiders produce vertically oriented orb-webs that contain viscous adhesive capture threads. This research will measure the stickiness, tensile strength, and extensibility of the prey capture threads from webs that are less highly organized than orb-webs, orb-webs containing cribellar thread, and orb-webs containing adhesive threads. The research will test the hypotheses that the precise and parsimonious architecture of orb-webs places a premium on the stickiness, tensile strength, and extensibility of capture threads; and that these characteristics become even more critical in vertical orb-webs whose orientation requires them to absorb greater forces because they intercept prey that fly faster. It will also show how stickiness of cribellar prey captur e threads is related to a spider's spinning anatomy and determine whether changes in spinning anatomy facilitated the origin of the orb-web. The information and insights gained from this comparison will answer major questions about the evolution of orb-webs, more fully characterize the functional properties of spider silk, and foster a more integrated view of spider web composition, structure, and function. These insights may ultimately be useful in the design of composite materials and adhesive or impact-absorbing structures.