Movie 1.

An example video recording of A. granulata behaviorally responding to the black-on-white loom. The video shows simultaneous orthogonal lateral views of the same chiton as well as a simultaneous screen recording of the overhead computer screen. In the beginning of the video, the chiton is slowly crawling towards the edge of the arena with sections of its girdle raised. When the looming black circle reaches a certain size, the chiton stops moving and lowers its girdle while simultaneously clamping to the substrate - which can be recognized by the lowering of the dorsal shell plates. This behavior is likely a defensive response, as the chiton is preparing itself for an impending attack by a looming predator.