Netrium interruptum (BREB.) LÃTKEM. The cells are 4-5 times longer than wide. The central part is cylindrical and gradually converging towards the broadly rounded off ends. The terminating vacuoles are big with a spherical crystal each. The chromatophores are clearly partitioned in four segments. Dimension: Length 200 â 350 µm, width 30 â 70 µm Ecology: Sporadic in little acidic fens and bogs, in addition, in the plankton of oligotrophic lakes. Occurrence: Ubiquitous, apart from Australia