Description
Unlike swimming in a 3D environment, swarming in micro-organisms is a collective behavior exhibited by rod-like bacteria driven by flagella on a semi-solid. It has been accepted that bacterial swarming is governed by short-range volume exclusion and long-range hydrodynamic interaction. Before the swarming state, the cell body elongates to adapt to the habitat change. Previous studies have mainly focused on the distribution of velocity and vorticity or the characteristic scales of swarming bacteria. The role of the aspect ratios of bacteria in the swarming behavior remains open. In this work, we experimentally investigate the above issue using a single strain of Vibrio alginolyticus with multi-aspect ratios during the expansion of the monolayer colony. We observe that the length of the bacteria has a wide range of heterogeneity, and different aspect ratios of bacteria play distinct roles in the formation of the swarming clusters and the swarming dynamics. Furthermore, interactions between aspect ratios benefit the efficiency of cell migration.
