Summary—The two flagella of Dinoflagellates have, up to now, been poorly described. They display different structures and different patterns of behaviour compared with other organisms. In addition, the two flagella are different from each other: the transverse flagellum is ribbon‐shaped and beats with a spiral undulation inside a furrow located around the cell body while the longitudinal flagellum has a larger diameter than simple flagella because it contains structures in addition to the axoneme and propagates essentially sinusoidal waves to push the cell.Ceratiumflagella are particularly interesting to study because they both show different types of movements and have complex structures in addition to the axoneme. We propose that the additional structures are responsible for the particular movements of Dinoflagellate flagella. The presence of food particles in vacuoles in the vicinity of the flagella pocket suggests that their flagellar apparatus may not only be a propulsive organelle but could also be involved in prey capt