{"title":"Ground Reaction Forces and Energy Exchange During Underwater Walking.","authors":"K M Gamel, S Pinti, H C Astley","doi":"10.1093/iob/obae013","DOIUrl":null,"url":null,"abstract":"<p><p>Underwater walking was a crucial step in the evolutionary transition from water to land. Underwater walkers use fins and/or limbs to interact with the benthic substrate and produce propulsive forces. The dynamics of underwater walking remain poorly understood due to the lack of a sufficiently sensitive and waterproof system to measure substrate reaction forces (SRFs). Using an underwater force plate (described in our companion paper), we quantify SRFs during underwater walking in axolotls (<i>Ambystoma mexicanum</i>) and Spot prawn (<i>Pandalus platyceros</i>), synchronized with videography. The horizontal propulsive forces were greater than the braking forces in both species to overcome hydrodynamic drag. In axolotls, potential energy (PE) fluctuations were far smaller than kinetic energy (KE) fluctuations due to high buoyant support (97%), whereas the magnitudes were similar in the prawn due to lower buoyant support (93%). However, both species show minimal evidence of exchange between KE and PE, which, along with the effects of hydrodynamic drag, is incompatible with inverted pendulum dynamics. Our results show that, despite their evolutionary links, underwater walking has fundamentally different dynamics compared with terrestrial walking and emphasize the substantial consequences of differences in body plan in underwater walking.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"6 1","pages":"obae013"},"PeriodicalIF":2.2000,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11191838/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Integrative Organismal Biology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1093/iob/obae013","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/1/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Underwater walking was a crucial step in the evolutionary transition from water to land. Underwater walkers use fins and/or limbs to interact with the benthic substrate and produce propulsive forces. The dynamics of underwater walking remain poorly understood due to the lack of a sufficiently sensitive and waterproof system to measure substrate reaction forces (SRFs). Using an underwater force plate (described in our companion paper), we quantify SRFs during underwater walking in axolotls (Ambystoma mexicanum) and Spot prawn (Pandalus platyceros), synchronized with videography. The horizontal propulsive forces were greater than the braking forces in both species to overcome hydrodynamic drag. In axolotls, potential energy (PE) fluctuations were far smaller than kinetic energy (KE) fluctuations due to high buoyant support (97%), whereas the magnitudes were similar in the prawn due to lower buoyant support (93%). However, both species show minimal evidence of exchange between KE and PE, which, along with the effects of hydrodynamic drag, is incompatible with inverted pendulum dynamics. Our results show that, despite their evolutionary links, underwater walking has fundamentally different dynamics compared with terrestrial walking and emphasize the substantial consequences of differences in body plan in underwater walking.
水下行走是从水中向陆地进化过渡的关键一步。水下步行者利用鳍和/或肢与底栖基质相互作用,产生推进力。由于缺乏足够灵敏和防水的系统来测量底质反作用力(SRFs),人们对水下行走的动力学仍然知之甚少。我们利用水下测力板(详见我们的论文),对斧头鱼(Ambystoma mexicanum)和斑节对虾(Pandalus platyceros)水下行走时的SRF进行了量化,并同步进行了录像。两个物种的水平推进力都大于制动力,以克服水动力阻力。在斧头鱼中,由于高浮力支持(97%),势能(PE)波动远远小于动能(KE)波动,而在对虾中,由于较低的浮力支持(93%),势能(PE)波动的幅度与动能(KE)波动的幅度相似。然而,这两个物种在 KE 和 PE 之间交换的证据极少,再加上流体阻力的影响,这与倒立摆动力学不相容。我们的研究结果表明,尽管两者在进化上有联系,但水下行走的动力学与陆地行走有本质区别,并强调了身体计划的差异对水下行走的重大影响。