until only phycoerythrin remained. Phycoerythrobilin, a type of red phycobilin pigment, is a chromophore discovered in cyanobacteria, chloroplasts of red algae and some Cryptomonads. Phycoerythrobilin is present in the phycobiliprotein phycoerythrin, the terminal acceptor of energy during the process of photosynthesis. The phycoerythrin was translocated into the thylakoid lumen with its chromophore composition altered; subsequently, phycobiliproteins with at least seven different absorption spectra evolved. Cryptomonas is distinguished by the purple phycoerythrin 566 as an accessory pigment, which gives the organisms a brownish color in appearance. Behaviour Cryptomonas are large in size, grow rather slowly, and are limited in nutrients. It also migrates between depths of water in order to reach depths that are ideal for photosynthesis and bacteriograzing, as well avoiding organisms that are their predators. Typically, they are found at depths of up to 102 meters and in a temperature range of -1.4 to 1.5 degrees Celsius. Cryptomonas seem to grow and survive with little competition. Cryptomonas swim actively, and they rotate while moving and sometimes swim in helical motion. Dimorphism Life history-dependent dimorphism was first described in organisms in 1986. In Proteomonas, another genus of Cryptophyceae, the two morphs revealed large differences in cell size which apparently led to its discovery and subsequent recognition. Cryptomonas has been discovered to be another genus that possesses the characteristic of dimorphism. Traditionally, Cryptomonas was considered to be 3 separate genera: Chilomonas, Cryptomonas and Campylomonas. Before further molecular analysis, Cryptomonas have been characterized by mainly morphological characters, such as cell size, cell shape, number and color of plastids. However, it was still difficult to define Cryptomonas due to insufficient understanding of morphological characters and less-than adequate visibility of living cells using light microscopy alone to observe the cell structures. Also, laboratories had lacked the condition to detect the different stages of particular organisms. The furrow-gullet system was used as a standard for organization of genera for many years. Most other Cryptophyte genera have either furrow or gullet, but Cryptomonas is one of the genera that possess a combination of the two, creating a furrow-gullet complex. The furrow-gullet complex is used by the cells to digest food for smaller organisms. Also, ejectisomes are found to be surrounding the complex. Previously, different textures of furrow plates are used to classify genera. For example, a furrow plate (extending posteriorly along one side of the ventral furrow-gullet complex) has been described as “scalariform” in Campylomonas yet