||This article may be expanded with text translated from the corresponding article in the German Wikipedia. (May 2012)|
Cryptomonas is the name-giving genus of the cryptomonads. It is common in freshwater habitats and often forms blooms in greater depths of lakes, or during winter beneath the ice. The cells are usually brownish in color, and have a slit-like furrow at the anterior. They are not known to produce any toxins and are used to feed small zooplankton, which is the food source for small fish in fish farming. In fact, the zooplankton, Ceriodaphnia quadrangula, feeds specifically on Cryptomonas erosa and nothing else. Many species of Crytomonas can only be identified by their molecular signatures. Cryptomonas can be found in several marine ecosystems in Australia.
This genus was originally separated into three different genera (Cryptomonas, Campylomonas, and Chilomonas), but after further investigation Campylomonas and Chilomonas were reclassified as a dimorphism under Cryptomonas. Species within Cryptomonas contain four genomes: the nucleus, the nucleomorph, the plastid, and mitochondrial genomes. The plastid genome contains 118 kilobase pairs and is a result of a phage from red alga, which is why Cryptomonas often has a red coloring.
Cell Structure, Metabolism, and Life Cycle
Cryptomonas cells are fairly larger than others; they average about 40 um in size and often take the shape of an oval or ovoid. They have two flagella that are fixed to the cell by four unique microtubular roots. In addition, the flagella are lined with hairs that allow for better movement. Cryptomonas are also photolithotrophs that contribute to oxygenic carbon fixation making them greatly influential to the carbon levels of fresh water environments. They rely on inorganic compounds such as water in order to perform photosynthesis. Replication of Cryptomonas occurs in early summer when fresh water species are also reproducing. Cryptomonas replicates via mitosis that only takes about ten minutes.
Cryptomonas function like Diatoms; they are large, grow slow, and are limited in nutrients. It also migrates between layers of water in order to reach depths that are ideal for photosynthesis and bacteriograzing, as well avoiding organisms that feed on phytoplankton. Typically they are found at depths of 0 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.
- Hoef-Emden K, Melkonian M (October 2003). "Revision of the genus Cryptomonas (Cryptophyceae): a combination of molecular phylogeny and morphology provides insights into a long-hidden dimorphism". Protist 154 (3-4): 371–409. doi:10.1078/143446103322454130. PMID 14658496.
- Hoef-Emden K (2005) Multiple independent losses of photosynthesis and differing evolutionary rates in the genus Cryptomonas (Cryptophyceae): Combined phylogenetic analyses of DNA sequences of the nuclear and the nucleomorph ribosomal operons. Journal of Molecular Evolution 60: 183-195. Abstract