Swimming, swarming, and cellular elongation of wild-type and pseudoswarmer cells. Swimming (A) was measured using semisolid Mot agar, and swarming (B) was measured on LB agar. (C to E) Phase-contrast micrographs of BB2000 (C), BB2204 (D), and YL1001 (E) taken after growth in LB broth. (F and G) Determination of the percent elongated cells in the populations of BB2000 (●), BB2204 (■), and YL1001 (▴). (F) Percentage of cells with a length of >7 μm; (G) percentage of cells with a length >3-fold greater than the floating standard (see Materials and Methods). Error bars represent standard deviations (n > 400).