Agelenids of the World

Systematics and Taxonomy of Agelenidae, a Worldwide distributed Spider Family

Gait characteristics of two fast-running spider species (Hololena adnexa and Hololena curta), including an aerial phase (Araneae: Agelenidae)

Publication Type:Journal Article
Year of Publication:2011
Authors:J. C. Spagna, Valdivia, E. A., Mohan, V.
Journal:Journal of Arachnology
Date Published:2011
ISBN Number:0161-8202
Keywords:/ Running gait characteristics / ]., Biophysics, Hololena adnexa, Hololena adnexa (Araneae)., Hololena curta (Araneae)., Hololena curta [Biomechanics / Kinematics / ] [Running, Locomotion

Funnel-web spinning spiders of the genus Hololena are capable of fast movements in a horizontal plane across a variety of challenging surfaces. We used two species, H. curia (McCook 1894) and H. adnexa (Chamberlin & Gertsch 1929), in experiments designed to reveal how they achieve remarkable speeds, occasionally exceeding 70 body lengths ([approximately]50 cm) per second. In high-speed recordings we found that spiders used their legs in alternating sets of four, distributed in staggered pairs along the body axis, resulting in an alternating-tetrapod gait. Increases in speed showed positive linear relationships with both frequency and stride length. There were also inverse, linear relationships in both species between speed and duty factor, meaning that increases in speed are associated with a decrease in the relative amount of time spent by the legs on the ground during each full leg cycle. By examining their duty factor vs. speed regressions, we found that spiders of both species were capable of aerial phases during high-speed running, with the transitional speed occurring at an average of 54 body lengths per second. We conclude that further experimentation with high-speed spiders and insects will likely show that a variety of species exhibits dynamically stable locomotion, including aerial phases.

URL:<Go to ISI>://ZOOREC:ZOOR14710073568
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