The key difference between euglenoids and Euglena is that euglenoids are a large group of single-cell organisms belonging to kingdom Protista while Euglena is the most widely studied representative genus of euglenoids.
Euglenoids are single-cell organisms that are mostly autotrophic. They belong to kingdom Protista and show both plant and animal features. Like plants, they photosynthesize. Like animals, they move and change their shapes. Moreover, they have two flagella; hence they are flagellated organisms. They live mostly in freshwater, especially water rich in organic matter. They can also live in marine water. There are 54 genera of euglenoids including Trypanosoma, Euglena and Eutreptia.
What are Euglenoids?
Euglenoids are single-cell flagellated organisms belonging to Kingdom Protista. They are a large group of algae. There are about 54 genera and 900 species in this group. They can live in freshwater, stagnant water and marine water. But they are commonly found in freshwater that is rich with organic materials. Euglena and Phacus are two representative genera of euglenoids. Euglenoids are unicellular except the colonial genus Colacium. Many euglenoids are spindle-shaped. Many of them also have chloroplasts. Hence, they are photosynthetic. Others feed by phagocytosis or by diffusion.
Furthermore, they have two flagella; one is long and functional while the other is short and does not protrude. Euglenoids do not have a cell wall. They have a protein-rich cell covering called the pellicle, which provides flexibility to euglenoids. Moreover, euglenoids have an eyespot which acts as a light-sensing device. They also have a contractile vacuole. It helps euglenoids to pump out excess water from their bodies. Furthermore, some euglenoids are capable of producing resting spores which are useful under unfavourable environmental conditions.
What is Euglena?
Euglena is the most widely known and studied genus of euglenoids. It is a single-celled organism belonged to phylum Protista. E. viridis is the most common species. However, there are 152 Euglena species. Euglena lives in freshwater and saltwater. They are also found in moist soils. It has both characteristics of plants and animals. They are photosynthesizing organisms that have chlorophylls. They move and change the shape like animals. Similar to other euglenoids, Euglena also has a pellicle made up of a protein layer.
During unfavourable environmental conditions, Euglena is able to form a protective wall around it and become dormant as a resting cyst. Euglena reproduces mainly by binary fission. Some species of Euglena are responsible for eutrophication.
What are the Similarities Between Euglenoids and Euglena?
- Euglena is a euglenoid.
- They belong to phylum Protista.
- Both are flagellated, single-celled organisms.
- They live in aquatic environments, mostly in freshwater.
- Both possess chlorophylls and chloroplasts.
- They are capable of photosynthesizing.
- Euglenoids and Euglena have a red eyespot which aids light sensing.
- They reproduce by binary fission, so they usually reproduce asexually.
- In addition, they have a cell covering called pellicle, which allows them to change their shapes.
What is the Difference Between Euglenoids and Euglena?
Euglenoids are a large group of unicellular flagellates belonging to kingdom Protista. Euglena is a genus of euglenoids. So, this is the key difference between euglenoids and Euglena. Most of the euglenoids are autotrophic while few are heterotrophic. Euglena species are mainly autotrophic.
The following infographic summarizes the difference between euglenoids and Euglena.
Summary – Euglenoids vs Euglena
Euglenoids are unicellular flagellates. They live in freshwater and damp soil. They have a cell covering called pellicle, which allows flexible body movements. There are many genera of euglenoids, including Euglena, Phacus, Eutreptia, Trachelomonas, and Peranema. Euglena is the most common and widely studied genus. Euglena species live in freshwater and brackish water that are rich in organic materials.
1. “Ehrenberg euglena viridis” By CG Ehrenberg 1838 – Die Infusionsthierchen, 1838 (Public Domain) via Commons Wikimedia
2. “Euglena mutabilis” By David J. Patterson – (CC BY 4.0) via Commons Wikimedia