The remarkable mechanical adaptability of arapaima (Arapaima gigas) scales has made them an important subject of study. However, no research has been conducted into their tribological properties, which are crucial for the protectability and flexibility of arapaimas. In this study, by combining morphological characterizations, friction experiments, and theoretical analyses, the relationship between the surface morphology and tribological properties of arapaima scales is determined. These results indicate that arapaima scales exhibit varying surface morphologies in different regions. More specifically, the exposed regions of scales feature grooves and a circulus, whereas the covered regions exhibit bumps. The specific surface morphology of arapaima scales produces varying tribological properties across different regions and sliding directions. The unique tribological properties of arapaima scales influence the forces received from predator attacks and neighboring scales, directly influencing the arapaima’s protective capabilities. This study provides new insights into the mechanisms of natural flexible dermal armors, and it has potential applications in personal protective systems.

巨骨舌鱼（ Arapaima gigas ）鳞片卓越的机械适应性使其成为重要的研究课题。然而，尚未对其摩擦学特性进行研究，而摩擦学特性对于巨骨舌鱼的保护性和灵活性至关重要。在本研究中，通过结合形态表征、摩擦实验和理论分析，确定了巨骨舌鱼鳞片的表面形态和摩擦学性能之间的关系。这些结果表明巨骨舌鱼鳞片在不同地区表现出不同的表面形态。更具体地说，鳞片的暴露区域具有凹槽和圆形，而被覆盖的区域则呈现凸起。巨骨舌鱼鳞片的特定表面形态在不同区域和滑动方向上产生不同的摩擦学特性。巨骨舌鱼鳞片独特的摩擦学特性会影响捕食者攻击和邻近鳞片所受到的力，从而直接影响巨骨舌鱼的保护能力。这项研究为天然柔性真皮装甲的机制提供了新的见解，并且在个人防护系统中具有潜在的应用。