Electron micrograph of dividing Caulobacter cells. One can see the holdfasts fixing the stalks on the ground and daughter cells carrying a single flagellum.

Caulobacter is being studied as a microbiological model organism due to its unusual cell differentiation and life cycle. Young cells are named swarmers as they are motile by a single flagellum. They seek a place to settle, lose their flagellum and form a stalk. When they divide flagellated swarmer cells are formed again.