Meeting Abstract
The ability for an organism to right itself (correcting the orientation of its body when overturned) in its environment is crucial to survival. Righting behavior can vary widely among taxa, and is largely based on body morphology. Tarantula righting behavior is not only needed in critical situations (falling and landing upside down), but is necessary after molting, when the spider/organism must intentionally turn itself upside down in order to shed the old cuticle. In order to describe and analyze the mechanics of this behavior, 33 external markers were painted on leg joints and abdomen. After being placed on their backs, the tarantulas were filmed simultaneously with four spatially calibrated, and time-synchronized, high speed video cameras. Righting behavior was digitized in Matlab to create a 3D model for visualization and analysis.We observed a stereotypical sequence where the fourth pair of legs is used to lever the cephalothorax off of the substrate, assisted by the third pair of legs. The first and second pairs of legs are typically used to make contact with the substrate via the scopular hairs. Once attachment to the substrate is made by one foot, the tarantula appears to pull itself over with the first and second legs, and push with the contralateral third and fourth legs. The efficiency with which tarantulas conduct this stereotypical behavior displays how such morphologically complex organisms can have an extraordinary amount of control when moving their bodies.
