Vega Christine M, Ashley-Ross Miriam A
Department of Biology, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA.
Integr Org Biol. 2020 Sep 21;2(1):obaa029. doi: 10.1093/iob/obaa029. eCollection 2020.
Animals live in heterogeneous environments must navigate in order to forage or capture food, defend territories, and locate mates. These heterogeneous environments have a variety of substrates that differ in their roughness, texture, and other properties, all of which may alter locomotor performance. Despite such natural variation in substrate, many studies on locomotion use noncompliant surfaces that either are unrepresentative of the range of substrates experienced by species or underestimate maximal locomotor capabilities. The goal of this study was to determine the role of forefeet and hindfeet on substrates with different properties during walking in a generalized sprawling tetrapod, the tiger salamander (). Adult salamanders ( = 4, SVL = 11.2-14.6 cm) walked across level dry sand (DS), semi-soft plaster of Paris (PoP), wet sand (WS), and a hard, noncompliant surface (table)-substrates that vary in compliance. Trials were filmed in dorsal and anterior views. Videos were analyzed to determine the number of digits and surface area of each foot in contact with the substrate. The surface area of the forelimbs contacting the substrate was significantly greater on DS and PoP than on WS and the table. The surface area of the hindlimbs contacting the substrate was significantly greater on DS than on all other substrates. There were no significant differences in the time that the fore- or hindfeet were in contact with the substrate as determined by the number of digits. We conclude that salamanders modulate the use of their feet depending on the substrate, particularly on DS which is known to increase the mechanical work and energy expended during locomotion owing to the fluid nature of its loose particles. More studies are needed to test a wider range of substrates and to incorporate behavioral data from field studies to get a better understanding of how salamanders are affected by different substrates in their natural environment.
生活在异质环境中的动物必须进行导航，以便觅食或捕获食物、保卫领地和寻找配偶。这些异质环境有各种不同粗糙度、质地和其他特性的基质，所有这些都可能改变运动性能。尽管基质存在这种自然变化，但许多关于运动的研究使用的是不符合实际的表面，这些表面要么不能代表物种所经历的基质范围，要么低估了最大运动能力。本研究的目的是确定在广义的 sprawled 四足动物虎螈行走过程中，前足和后足在具有不同特性的基质上所起的作用。成年蝾螈（n = 4，SVL = 11.2 - 14.6 厘米）走过水平的干沙（DS）、半软的巴黎石膏（PoP）、湿沙（WS）和坚硬、不符合实际的表面（桌子）——这些基质在顺应性方面各不相同。试验从背侧和前侧视角进行拍摄。对视频进行分析，以确定每只脚与基质接触的趾数和表面积。前肢与基质接触的表面积在 DS 和 PoP 上显著大于在 WS 和桌子上的。后肢与基质接触的表面积在 DS 上显著大于在所有其他基质上的。根据趾数确定，前足或后足与基质接触的时间没有显著差异。我们得出结论，蝾螈会根据基质调节其足部的使用，特别是在 DS 上，由于其松散颗粒的流体性质，已知在 DS 上行走时会增加机械功和能量消耗。需要更多研究来测试更广泛的基质范围，并纳入野外研究的行为数据，以更好地了解蝾螈在自然环境中如何受到不同基质的影响。
