Population heterogeneity revealed in morphometric analysis of densely populated microbial swarm collectives.

Uncovering cell morphology within communities is crucial to understanding how collective groups of organisms can function and adapt to their environments. Key questions remain regarding how cell morphology influences population behaviors and whether uniformity is required for coordinated actions, such as collective migration. These gaps hinder the ability to describe how individuals contribute to collective adaptability and coordinated behaviors. We developed an image capture and analysis pipeline, named Swarmetrics, for studying individual cells that are within dense bacterial communities, can participate in collective behaviors, and may have irregular cell morphologies. We used IMPORTANCE: Understanding how individual cell morphology shapes collective behavior is crucial for uncovering principles of organization across biological systems. We developed an image analysis pipeline, Swarmetrics, and revealed unexpected phenotypic heterogeneity among cells during bacterial collective migration. These results raise questions about the necessity and impact of uniformity-in shape and behaviors-during bacterial collective actions. Swarmetrics also opens the door for quantitative analysis of irregularly shaped cells in dense communities.