Meeting Abstract
Autotomy, self-amputation of an appendage, is a common adaptation observed in a variety of animal taxa that evolved to increase the chance of surviving a predatory encounter. Despite this benefit, there can be severe negative consequences on locomotor performance, which is crucial for avoiding predators and finding food, mates, and suitable habitat. In spiders, studies have found that leg autotomy hinders sprint speeds and prey capture abilities. However, to our knowledge, no study has examined the impact that leg autotomy has on speed and kinematics of spider locomotion on inclined substrates. Therefore, using a repeated-measures design, spiders were run on one horizontal substrate and two inclined (45° and 90°) substrates both before and after autotomy of one of the first pair of legs in the cellar spider (Pholcus manueli). Speed, stride length, stride cycle time, and duty factor were measured in all remaining legs. We found that speed and stride length decreased with increasing incline despite small body size. However, stride length increased following autotomy during non-vertical locomotion, likely to compensate for the missing leg. We found that autotomy and incline interact to affect stride cycle time, which was highest in autotomized spiders at 45° inclines. Duty factor increased in the first leg opposite of the one autotomized at all inclines. Pholcid spiders appear to compensate for limb loss differently on various inclines. Future studies should compare the effect of removal of different legs on performance and kinematics to get a better understanding of the negative consequences of leg autotomy in nature.
