NSF Postdoctoral Fellowship in Biology FY 2019: Rough skin: microstructural and fluid dynamic studies of elasmobranch skin to understand how denticle morphology affects locomotion

本行动资助NSF 2019年度生物学博士后研究奖学金，利用生物馆藏进行研究。该奖学金支持研究和培训将以创新的方式利用生物收集的研究员。这项研究的重点是鱼皮的形态，特别是鲨鱼和鳐鱼身上被称为小齿的微小鳞片。小齿有许多被提出的功能，包括保护免受捕食者的侵害、减少磨损和改变身体上的水流。众所周知，齿的形状特征在物种之间以及个体身体的不同位置上都是不同的。小齿的形状被认为可以通过减少水动力阻力来改变鱼体内的水流。这些鳞片的功能意义特别令人感兴趣，因为鲨鱼和鳐鱼使用许多不同的游泳方式，并且有许多不同的小齿大小和形状。通过比较皮肤形态和功能，他将回答有关鱼类生物学的问题，包括进化、运动和栖息地。研究员将通过学习新技术，包括3D打印皮肤的机器人测试，获得对鱼类功能形态的理解。研究结果对于人类学习水下运动也很重要。该研究员将与大西洋白鲨保护协会密切合作，为对鲨鱼研究感兴趣的年轻女孩开发一个动手教学研讨会。该研究员将使用来自哈佛大学比较动物学博物馆的板鳃目标本，对齿状结构进行大规模的比较分析。该研究员将接受多种三维（3D）成像技术的培训，以检查采用各种运动模式（即轴向波动推进器和胸鳍推进器）的物种的小齿形态。该研究员将使用基于凝胶的轮廓测量法，该方法确定表面计量变量（即齿状体粗糙度），并结合微型计算机断层扫描，沿动物身体的各个部位创建单个齿状体的3D模型。这些模型将用于高分辨率3D打印机，用于定量流体动力学测试的柔性材料，以研究皮肤小齿产生的精细流体动力学。了解牙齿形态对弹性鳃的水动力功能和生态学的影响，对于理解弹性鳃的结构和功能进化，以及为人类设计更高效的水下运动仿生材料具有重要意义。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。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2019, Research Using Biological Collections. The fellowship supports research and training of the fellow that will utilize biological collections in innovative ways. This research focuses on the morphology of fish skin, specifically, the microscopic scales called denticles on sharks and rays. Denticles have many proposed functions, including protection from predators, abrasion reduction, and alteration of water flow over the body. Shape characteristics of denticles are known to differ among species as well as along different positions of the body within an individual. Denticle shape is thought to alter water flow along the body of fish, by decreasing hydrodynamic drag. The functional significance of these scales is of particular interest because sharks and rays use many different ways of swimming, and there are many different denticle sizes and shapes. By comparing skin form with function, the fellow will answer questions about fish biology, including evolution, locomotion, and habitat. The Fellow will gain understanding of fish functional morphology by learning new techniques, including robotic testing of 3D printed skin. The results will also be important for learning about underwater locomotion for human use. The Fellow will work closely with the Atlantic White Shark Conservancy to develop a hands-on teaching seminar for young girls interested in shark research. The fellow will use elasmobranch specimens from the Harvard Museum of Comparative Zoology to conduct a large-scale comparative analysis of denticle shape. The Fellow will be trained in multiple three-dimensional (3D) imaging techniques to examine denticle morphology of species that employ various locomotor modes (i.e. axial-undulatory and pectoral-fin propulsors). The Fellow will use gel-based profilometry, which determines surface metrology variables (i.e. denticle roughness) together with micro-computed tomography, to create 3D models of individual denticles along various parts of an animal's body. These models will be used in a high-resolution 3D printer to produce a flexible material for quantitative hydrodynamic testing to investigate the fine-scale fluid dynamics produced by the skin denticles. Understanding how the morphology of the denticles contributes to hydrodynamic function and the ecology of elasmobranchs is important for understanding the structural and functional evolution of elasmobranchs and to design more efficient biomimetic materials for underwater locomotion for human use.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.