Energy and time optimal trajectories in exploratory jumps of the spider Phidippus regius

Mostafa R A Nabawy,Russell J Garwood,William I Sellers,Girupakaran Sivalingam,William J Crowther

doi:10.1038/s41598-018-25227-9

Mostafa R A Nabawy, Russell J Garwood + Show 3 more

Open Access

https://doi.org/10.1038/s41598-018-25227-9

Copy DOI

Abstract

Jumping spiders are proficient jumpers that use jumps in a variety of behavioural contexts. We use high speed, high resolution video to measure the kinematics of a single regal jumping spider for a total of 15 different tasks based on a horizontal gap of 2–5 body lengths and vertical gap of +/−2 body lengths. For short range jumps, we show that low angled trajectories are used that minimise flight time. For longer jumps, take-off angles are steeper and closer to the optimum for minimum energy cost of transport. Comparison of jump performance against other arthropods shows that Phidippus regius is firmly in the group of animals that use dynamic muscle contraction for actuation as opposed to a stored energy catapult system. We find that the jump power requirements can be met from the estimated mass of leg muscle; hydraulic augmentation may be present but appears not to be energetically essential.

Highlights

Jumping is a unique form of animal locomotion in which a rapid extension of the legs in contact with the ground provides sufficient impulse for significant airborne translation
The main aim of the present study is to provide deeper understanding of the mechanics of jumps, and how the jumping spider P. regius adapts its jumping style depending on the jumping task it is presented with
The morphological data provided in the Supplementary Files S1 will allow future development of more sophisticated kinematic models that can be used for motion reconstruction and biomechanical analysis going forward

Summary

Introduction

Jumping is a unique form of animal locomotion in which a rapid extension of the legs in contact with the ground provides sufficient impulse for significant airborne translation. Parry and Brown[19] used this relationship to estimate the acceleration of the jumping spider S. pubescens during take-off, calculate propulsive force and torques at the hinge joints, and estimate the pressure required to cause this. They conclude that hydraulic forces are involved in the jump, in part because the estimated pressure is within a factor of two of pressures observed in the house spider, and in part due to the observation that leg spines become erect at take-off, which they propose reflects increased haemolymph pressure. It is possible that increased tension in the safety line towards the end of the jump could produce a negative nose-down pitching moment, and reduce the attitude of the body prior to landing[22]

Objectives

Methods

Results

Conclusion