Integrative Biology Department, University of South Florida, Tampa, FL 33620, USA
Integrative Biology Department, University of South Florida, Tampa, FL 33620, USA.
J Exp Biol. 2020 Sep 6;223(Pt 17):jeb211706. doi: 10.1242/jeb.211706.
Plethodontid salamanders inhabit terrestrial, scansorial, arboreal and troglodytic habitats in which clinging and climbing allow them to access additional food and shelter as well as escape from unfavorable temperature and moisture conditions and ground-dwelling predators. Although salamanders lack claws and toe pads found in other taxa, they successfully cling to and climb on inclined, vertical and inverted substrates in nature. Maximum cling angle was tested on smooth acrylic, and the relationship between cling angle, body mass and surface area of attachment (contact area) was investigated. This study found that many salamander species can cling fully inverted using only a portion of their ventral surface area to attach. Salamanders fall into three functional groups based on mass and maximum cling angle: (1) high-performing, very small salamanders, (2) moderately high performing small and medium-sized salamanders and (3) low-performing large salamanders. They show significant differences in maximum cling angle, even between species of similar mass. In species of similar mass experiencing significantly different detachment stress (resulting from significantly different contact area), differences in morphology or behavior affect how much body surface is attached to the substrate. High performance in some species, such as , is attributable to large contact area; low performance in a similarly sized species, , is due to behavior that negatively impacts contact area. There was no clear evidence of scaling of adhesive strength with increasing body size. Salamander maximum cling angle is the result of morphology and behavior impacting the detachment stresses experienced during clinging.
穴居螈栖息于陆生、攀爬、树栖和洞穴生境中，它们通过紧贴和攀爬来获取更多的食物和庇护所，同时逃避不利的温度和湿度条件以及地面捕食者。虽然穴居螈没有其他分类群中发现的爪子和脚趾垫，但它们能够成功地紧贴和攀爬于自然环境中倾斜、垂直和倒置的基质表面。在光滑的亚克力上测试了最大紧贴角度，并研究了紧贴角度、体重和附着表面积（接触面积）之间的关系。本研究发现，许多穴居螈物种可以仅使用腹侧表面的一部分完全倒置紧贴。穴居螈可根据体重和最大紧贴角度分为三个功能组：（1）高表现型、非常小的穴居螈，（2）中高表现型的小和中型穴居螈，以及（3）低表现型的大型穴居螈。即使是体重相似的物种，它们的最大紧贴角度也存在显著差异。在经历明显不同的脱离应力（源自明显不同的接触面积）的相似体重的物种中，形态或行为的差异会影响附着到基质的体表面积。某些物种（如）的高表现性能归因于较大的接触面积；而相似体型的物种（如）的低表现性能则是由于行为会负面影响接触面积。没有明显证据表明随着体型的增大而导致粘附强度的缩放。穴居螈的最大紧贴角度是形态和行为影响紧贴时所经历的脱离应力的结果。
