Arthropod parasites of marine mammals: convergent physical solutions of living on aquatic hosts

海洋哺乳动物被各种体内和体外寄生虫感染，这些寄生虫在附着于宿主时面临多重挑战。海洋哺乳动物的节肢动物寄生虫已经发展出专门的解剖学适应性，以确保它们对水生宿主的控制，并发展出复杂的策略，以使浮游动物和两栖野生动物之间的传播成为可能。我们选择了三种节肢动物物种，已适应不同的海洋主机：海豹虱，作为陆地起源的吸血昆虫和鲸鱼虱，作为海洋起源的片足类甲壳动物，以及呼吸螨从海豹的气道。所有这三个物种都有活动的幼虫，在与宿主个体的身体接触过程中传播。它们的外骨骼通过适应材料和设计而进化，以适应群居和潜水的海洋哺乳动物。人们对海洋哺乳动物节肢动物寄生虫的生物学知之甚少，但对它们在这种具有挑战性的环境中生活的物理方面更是知之甚少。新的方法需要提供更多的洞察力，在结构设计和机械性能和知识的物理原理，他们的附件和运动。最先进的仪器，如微型CT，共聚焦激光扫描显微镜和冷冻扫描电镜将提供基本的知识，形态适应的寄生虫，使他们的附件在主机潜水，拖出来，以及他们如何忍受电流和社会互动。比较昆虫、甲壳类和蛛形纲动物不同生命周期阶段在不同表面上的运动能力和发育特征，以了解它们运动系统的功能形态。寄生虫对宿主适合度的降低在寄生虫与宿主的界面处最为明显。鲸虱阻碍皮肤伤口的愈合过程，海豹虱是丝虫病和病毒病的媒介。我们将利用感染组织的组织病理学来研究宿主-寄生虫界面，以确定对宿主组织的结构损伤。由不同的寄生虫物种保持的摩擦力和粘附力进行了研究，定制的微力测试装置。拟议的项目将提供有关选定的节肢动物寄生虫物种的附着装置的结构，材料特性和附着性能之间的关系的知识。有关它们的运动和招募动力学的数据将首次进行研究，研究结果将为开发生物启发的表面和专门用于增强或减少摩擦力或粘附力的系统提供新的途径。在不同的个体发育阶段，其在生命周期中的作用的附件设备的属性的新数据可能会揭示有趣的兽医方面。

Marine mammals are infected by a variety of endo- and ectoparasites which face multiple challenges when having to attach to their host. Arthropod parasites of marine mammals have developed specialized anatomical adaptations, to secure their hold on aquatic hosts, and sophisticated strategies to enable transmission between vagile pelagic and amphibious wildlife. We have chosen three arthropod species that have adapted differently to their marine hosts: seal lice, as hematophagous insects of terrestrial origin and whale lice, as amphipod crustaceans of marine origin, as well as respiratory mites from the airways of seals. All three species have motile larvae that are transmitted during bodily contact of host individuals. Their exoskeleton has evolved by adapting materials and design to survive on gregarious and diving marine mammals. Little is known about biology of marine mammal arthropod parasites, but even less about physical aspects of their life in this challenging environment. Novel approaches are required to provide more insight in structural design and mechanical properties and knowledge on physical principles of their attachment and locomotion. State of the art instrumentation, such as micro-CT, confocal laser scanning microscopy and Cryo-SEM will provide basic knowledge on morphological adaptations of parasites that enable their attachment to hosts during dives, haul-out and how they endure currents and social interactions. The locomotive abilities of the different life cycle stages on various surfaces and developed features of insect, crustacean and arachnid species are compared to understand functional morphology of their locomotory system. Parasites reduce the fitness of their host most obviously at the interface between parasite and host. Whale lice impede healing processes of skin wounds and seal lice are vectors for filarial and viral diseases. We will investigate the host-parasite interface using histopathology of infected tissues to define the structural damage to host tissues. Friction and adhesion forces maintained by the different parasite species are investigated by custom made microforce testing devices. The proposed project will provide knowledge on relationships between structure, material properties and attachment performance of attachment devices in selected arthropod parasite species. Data on their locomotion and recruitment dynamics will be studied for the first time and the results will provide new avenues for development of biologically-inspired surfaces and systems specialized for enhancement or reduction of frictional or adhesive forces. New data on the properties of attachment devices in different ontogenetic stages and their role in the life cycle can potentially reveal interesting veterinary aspects.