Pillai Rishab Rajan, Riedel Jendrian, Wirth Wytamma, Allen-Ankins Slade, Nordberg Eric, Edwards Will, Schwarzkopf Lin
College of Science and Engineering, James Cook University, Townsville, Queensland, Australia.
School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia.
Proc Biol Sci. 2025 Sep;292(2054):20251362. doi: 10.1098/rspb.2025.1362. Epub 2025 Sep 3.
Morphological adaptations facilitate effective movement within habitats. Claws are among the most common adaptations enabling organisms to use inclined and vertical surfaces. However, some taxa have evolved adhesive pads in addition to claws, with claws suggested to be more effective at gripping coarse surfaces, while pads attach better to fine-grained surfaces. Using test surfaces that represented the range of surface roughness used by six species of diplodactylid geckos in nature, we quantified the role of claws and pads acting together, and of pads alone. We examined two functional traits, attachment (on inclines, 45° and vertical surfaces, 90°) and clinging ability (on inclines only). Claws were critical to attachment on vertical surfaces, and attachment declined linearly with decreasing surface roughness. Although attachment was lowest on fine-grained surfaces, this was where claws had the greatest functional contribution. Clinging ability also declined linearly with decreasing surface roughness, where claws played an additive role. Our study highlights novel results describing the function of gecko adhesive systems on different surfaces and suggests a clade-specific interaction of claws and pads. Specifically, we highlight that pads alone can be capable of attachment on rough surfaces, with claws contributing more on fine-grained surfaces.
形态学适应有助于生物在栖息地内有效移动。爪子是使生物体能够利用倾斜和垂直表面的最常见适应特征之一。然而，一些类群除了爪子之外还进化出了粘性脚垫，有研究表明爪子在抓握粗糙表面时更有效，而脚垫在附着于细颗粒表面时效果更佳。我们使用了代表六种双足守宫在自然环境中所使用的表面粗糙度范围的测试表面，量化了爪子和脚垫共同作用以及仅脚垫作用时的效果。我们研究了两个功能特性，即附着能力（在45°倾斜面和90°垂直面上）和 cling 能力（仅在倾斜面上）。爪子对于在垂直表面上的附着至关重要，并且附着能力随着表面粗糙度的降低而呈线性下降。尽管在细颗粒表面上附着能力最低，但这却是爪子发挥最大功能作用的地方。cling 能力也随着表面粗糙度的降低而呈线性下降，在这方面爪子起到了累加作用。我们的研究突出了描述壁虎粘性系统在不同表面上功能的新结果，并表明爪子和脚垫之间存在特定类群的相互作用。具体而言，我们强调仅脚垫就能在粗糙表面上实现附着，而爪子在细颗粒表面上的作用更大。
