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Click on images for larger format |
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Name derivation: |
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Cryptomonas Ehrenberg 1831 was the first cryptomonad described. ‘Cryptic monad’ Gr. Crypto- hidden; -monas – flagellated cell
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Classification: |
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Cryptomonas Ehrenberg 1831; 45 of 173 species descriptions are currently accepted taxonomically (Guiry and Guiry 2013). Of the 173 historic species descriptions, a recent revision recognizes 14 species based on rigorous molecular classification based on nucleomorph SSU rDNA sequences, nuclear ITS2 and LSU rDNA sequences (Hoef-Emden 2007).Order Cryptomonadales, Family Cryptomonadaceae .
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Morphology: |
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Biflagellate unicells 3 – 50 µm in length, asymmetric and flattened, often with a visible food groove offset near the apical end. Flagella insertion is subapical. Contain many discoid chloroplasts. In most species an oral groove lined with ejectosomes is evident. One flagellum bears a single row of ‘flimmer’ (from German ‘flimmern’ meaning flicker or glimmer) or ‘mastigonemes, also called ‘tinsel hairs’ or ‘flagellar hairs’, that apparently originate in the cisternae of the endoplasmic reticulum. The other flagellum has two rows of hairs. The flimmer in Cryptomonas have an average length of 17.6 nm (Heath et al. 1970).
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Phycobilins: |
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Cryptomonads have accessory photopigments phycocyanin and phycoerithrin. Cell color varies with chromatic adaptation – varying concentration of these phycobilins and chlorophylls a and c.Phycoerythrin absorption spectrum in Cryptomonas sp. coincides with the phototactic action spectrum (Watanabe and Furuya 1974).
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Bactivery: |
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Low levels of bacterial ingestion by two cultures of Cryptomonas (C. ovata and C. erosa) and a population collected from a humic mesotrophic lake, using fluorescent polystyrene microspheres. However <2% of carbon content per day was accumulated through bactivory (Tranvik, Porter and Sieburth 1989).
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Diaphototaxis: |
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Cryptomonas sp. orients its cell perpendicular to incident light (diaphototaxis) (Rhiel, Hader and Wehrmeyer 1988).
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Similar genera: |
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Rhodomonas differs primarily in abundance of phycoerithrin giving it a red color.
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Habitat: |
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Fresh to slightly brackish water. Widespread – found on all continents (Guiry and Guiry 2013). |
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References: |
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Ehrenberg CG (1831) Symbolae physicae seu Icones et Descriptiones Animalium Evertebratorum sepositis Insectis quae ex itinere per Africanum borealem et Asiam occidentalem Friderici Guilelmi Hemprich et Christiani Godofredi Ehrenberg medicinae et chirurgiae doctorum studio novae aut illustratae redierunt. Mittler, Berlin. Guiry, M.D. and G.M. Guiry 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 30 April 2013. Heath, J.B., A.D. Greenwood and H.B. Griffiths 1970. The origin of flimmer in Saprolegnia, Dictyuchus, Synura and Cryptomonas. Journal of Cell Science 7:445-461. Hoef-Emden, K. 2007. Revision of the genus Cryptomonas (Cryptophyceae) II: incongruences between the classical morphospecies concept and molecular phylogeny in smaller pyrenoid-less cells. Rhiel, E., D.P. Hader and W. Wehrmeyer 1988. Diaphototaxis and gravitaxis in a freshwater Cryptomonas. Plant Cell Physiology 29(50;755-760. Tranvik, L.J., K.G. Porter and J. McN. Sieburth 1989. Occurrence of bacterivory in Cryptomonas, a common freshwater phytoplankter. Oecologia 78:473-476. Watanabe, M., and M. Furuya 1974. Action spectrum of phototaxis in a cryptomonad alga, Cryptomonas sp. Plent Cell Physiology 15(3):413-420. |
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