Dynamic leg deformations drive omnidirectional strike maneuvers in flat spiders


Meeting Abstract

24-4  Thursday, Jan. 5 11:00 – 11:15  Dynamic leg deformations drive omnidirectional strike maneuvers in flat spiders ZENG, Y.*; CREWS, S.; Univ. of California, Merced; California Academy of Sciences yzeng7@ucmerced.edu

Legged animals maneuver by generating bilaterally asymmetric ground reaction forces. Here, we show that the flattie spiders (Selenopidae), a group of ambush predators, perform rapid reorientations when striking prey, exhibiting the fastest turning maneuvers ever documented in legged animals. This maneuver capability allows them to strike toward any direction within an approximate five-body-length radius, surpassing others in the range of attack. We found these strike maneuvers are driven by bilaterally asymmetric deformations of a few legs which rapidly change the functional length and orientation to generate bursts of linear and angular momentums. Also, other legs perform rapid flexions to regulate whole-spider inertia, significantly enhancing the rotational speed. Based on the spider’s jointed musculoskeletal framework, we derive a generalized template for body maneuvers driven by leg deformations and highlight the functional significance of jointed, laterigrade legs for enhancing maneuverability.

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