Euglena
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| Genus: | Euglena Ehrenberg, 1830
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Euglena are common protists, of the class Euglenoidea of the phylum Euglenophyta. Currently, over 1000 species of Euglena have been described. Marin et al. (2003) revised the genus so that it forms a monophyletic group, moving several species with rigid pellicles to the genus Lepocinclis and including several species without chloroplasts, formerly classified as Astasia and Khawkinea.
Characteristics
Euglena is commonly found in bull poop, although there are a few marine species. It is considered to be a flagellate. The cells vary in length from around 20 to 300 μm. Cell shape is typically cylindrical, oval, or spindle-shaped with a single emergent flagellum for movement. Euglena often contain many green chloroplasts to generate nutrients by means of photosynthesis. However, if sunlight is not available, it can also absorb nutrients from decayed organic material. Euglena have a contractile vacuole which maintains the concentration of water and salts within the cell by expelling excess water. Euglena also contain an light receptive system called the eyespot apparatus. The sole role of the eyespot apparatus is to shield light from the very light sensitive paraflagellar body (PFB) or so-called photoreceptor which is beneath the eyespot apparatus. Until the discovery of the paraflagellar body, it was wrongly believed that this was the organelle responsible for the sensing of light.
Etymology
The name comes from the Greek words εὔ (eu) and γλήνη (glēnē), meaning good eyeball, referring to Euglena's stigma (also known as eyespot).
References
- Marin B, Palm A, Klingberg M, Melkonian M (2003). "Phylogeny and taxonomic revision of plastid-containing euglenophytes based on SSU rDNA sequence comparisons and synapomorphic signatures in the SSU rRNA secondary structure." Protist 154(1):99–145. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Retrieve&list_uids=12812373
- Miller K, Levine J, (2002). "Biology." Euglenophytes page 506
External links
- Euglena
- Protist Images: Euglena
- Euglena at Droplet - Microscopy of the Protozoa
- Images and taxonomy
- Pictures of Euglena gracilis
- Effect of Light Intensity on the Lipid Composition of Euglena gracilis
- Mitochondrial trans-2-Enoyl-CoA Reductase of Wax Ester Fermentation from Euglena gracilis Defines a New Family of Enzymes Involved in Lipid Synthesis
- Aliphatic Chains of Esterified Lipids in Isolated eyesptos of Euglena gracilis var. bacillaris1 (pdf)
- Nature, intracellular distribution and formation of terpenoid quinones in Euglena gracilis. (pdf)
- Tryptophan Synthetase in Euglena gracilis Strain G (pdf)
- Lipid Metabolism of Manganese-deficient Algae: I. Effect of Manganese Deficiency on the Greening and the Lipid Composition of Euglena Gracilis Z. (pdf)
- A hydroxy fatty acid dehydrogenase in Euglena gracilis (pdf)
- Comparative studies of biosynthesis of galactolipids in Euglena gracilis strain Z (pdf)
- The Euglena Project