Abstract
This paper describes the unusual swimming mechanism of a small beetle Guignotus japonicus. Usual diving beetles swim by flexing their hindlegs together simultaneously like oars. Diving beetles Guignotus japonicus move their legs alternately. The locomotive behavior of the small diving beetle Guignotus japonicus is analyzed by a high speed video camera system. The velocity changes of the hindleg motion are measured. The relation between the hindleg velocity and swimming velocity of the diving beetle is revealed. Experimental data is useful to a design of a micro robot.
