Bicosoeca petiolata is a very common flagellate in my sampling sites. It is best observed on floating coverslips, where colonies like to settle. The cell are anchored in the lorica with the short, posterior flagellum. The longer, anterior flagellum is used for catching food (bacteria) and performs sinuous and wave-like movements (s. figs. 2 and 3b). When disturbed, the flagellate retracts and the long flagellum is retracted in a spiral pattern (s. fig. 3a). Unlike most other colorless flagellates that feed heterotrophically, the flagella do not originate at an apically located mouth opening, but in the “shoulder area” in the anterior third of the cell (s. fig. 3b).