This species (A. poecilochroum?) contains a number of symbiotic blue green algae (identifiable as such from the colour). Many protists contain blue green algae, and this has been used by some to create a taxon for protists with these symbionts, imagining that they represent some kind of intermediary between bacterial and eukaryotic life. The equatorial flagellum can be seen as it curves round the cell, the groove in which the longitudinal flagellum normally resides is evident, although the flagellum is not visible.