PhD Thesis

Faster than the Blink of an Eye:

New insights into neuromuscular activations of arboreal snakes

Arboreal snakes such as the amazon tree boa (Corallus hortulanus) are able to cantilever large sections of their body for very long periods of time with seemingly minimal muscular effort. From this cantilevered position they exert quick strikes as well as compensate for any movement of the object from which they cantilever. The mechanisms of muscle coordination required for the dynamic switch between resting and strike have been hypothesized for terrestrial puff adders (Bitis arietans) to result from the vast and unique musculo-tendon arrangement of the snake’s epaxial muscles put under pre-strike tension, i.e. a spring-like mechanism where the snake is able to store a large amount of energy in tendons which can then be later quickly released. Furthermore, while muscle activity during gap crossing or extension activities has been described for an arboreal species, it is not clear how the stationary snake’s muscles compensate for perturbations of the anchoring object, e.g. as happens in the wild with a branch swaying in the breeze. Using a self-built high-speed 3D tracking system along with a novel method for collecting chronic multi-electrode bipolar electromyography (EMG) information, our new data is not only unsupportive of the spring-like strike hypothesis but provides insights to the muscle coordination required for stabilization in a moving, as well as stationary, environment.