Difference Between Euglena and Paramecium

Main Difference – Euglena vs Paramecium

Euglena and Paramecium are two types of unicellular organisms. Both Euglena and Paramecium are aquatic organisms that belong to the kingdom Protista. The difference between the two lies in body structure, locomotion, and feeding modes. The main difference between Euglena and Paramecium is that Euglena can be either animal-like or plant-like organisms whereas Paramecium is an animal-like organism. Only Euglena consists of chloroplasts. Paramecium does not contain its own chloroplasts. But, it swallows green algae. Therefore, Euglena is either heterotrophic or autotrophic whereas Paramecium is autotrophic. Euglena uses flagella for locomotion while Paramecium uses cilia. Both sexual and asexual reproduction occur in Paramecium. But asexual reproduction is the only reproduction method of Euglena.

Key Areas Covered

1. What is Euglena
– Definition, Structure, Locomotion, Feeding Mode
2. What is Paramecium
– Definition, Structure, Locomotion, Feeding Mode
3. What are the Similarities Between Euglena and Paramecium
– Outline of Common Features
4. What is the Difference Between Euglena and Paramecium
– Comparison of Key Differences

Key Terms: Autotrophs, Chloroplasts, Cilia, Euglena, Flagella, Heterotrophs, Paramecium, Protists

What is Euglena

Euglena refers to a green, unicellular, freshwater organism with a flagellum. It consists of characteristics of both animals and plants. Euglena consists of chloroplasts. If the light is available, it undergoes photosynthesis. These chloroplasts are scattered throughout the cell. Euglena contains pyrenoids, which are micro-compartments inside the chloroplast, operating carbon-concentrating mechanisms. The food is stored in the form of starch granules in Euglena. The structure of the body of Euglena is shown in figure 1.

Difference Between Euglena and Paramecium

Figure 1: Euglena Structure

Euglena possesses some animal-like characteristics as well. It has an eyespot for the detection of light. Euglena does not have a cell wall. Pellicle, which is made up of a protein layer, is arranged around the cell. The pellicle is held by microtubules. The sliding of the strips of the pellicle provides flexibility and contractility to Euglena. The sliding process is called metaboly. The gullet of the Euglena serves as a reservoir of food. Euglena possesses a flagellum for its locomotion. It also possesses a contractile vacuole called myoneme, which helps in locomotion. This contractile vacuole is also involved in the excretion and osmoregulation.

What is Paramecium

Paramecium refers to a unicellular, freshwater animal with a characteristic slipper-like shape. The length of a Paramecium can be about 0.3 mm. The outer surface of the Paramecium consists of cilia. Cilia are important for locomotion. The forward movement is achieved by the backward beats of cilia, and the backward movement is achieved by the forward beats of cilia. A large macronucleus and a micronucleus can be identified inside the Paramecium cell. The oral groove is located on one side of the organism. It forms the gullet and ends up with a cytostome. The cilia are also involved in feeding by moving food into the gullet. The structure of the body of a Paramecium is shown in figure 2.

Figure 2: Paramecium Structure

The ingested food is digested inside a vacuole, and the wastes are eliminated through the anal pore. Paramecium asexually reproduces by binary fission under favorable conditions. Under unfavorable conditions, Paramecium reproduces sexually by conjugation. Paramecium is also sensitive to changes in the environment such as temperature, light, chemicals, as well as touch.

Similarities Between Euglena and Paramecium

Both Euglena and Paramecium are eukaryotic, microorganisms which belong to the kingdom Protista.
Both Euglena and Paramecium are aquatic organisms.
Both Euglena and Paramecium are sensitive to the light.
Both Euglena and Paramecium contain chloroplasts to undergo photosynthesis.
Both Euglena and Paramecium can be heterotrophs.
Both Euglena and Paramecium consist of food vacuoles inside the cell.
Both Euglena and Paramecium consist of a pellicle, which provides a shape to the cell.

Definition

Euglena: Euglena refers to a green, unicellular, freshwater organism with a flagellum.

Paramecium: Paramecium refers to a unicellular, freshwater animal with a characteristic slipper-like shape.

Structure

Euglena: Euglena can be either animal-like or plant-like organism.

Paramecium: Paramecium is an animal-like organism.

Chloroplasts

Euglena: Euglena contain chloroplasts.

Paramecium: Paramecium does not contain its own chloroplasts. But, it swallows green algae.

Heterotrophic Nutrition Mode

Euglena: Euglena ingests food particles.

Paramecium: Paramecium catches food by predation.

Feeding Mechanism

Euglena: Euglena either undergo photosynthesis or ingest food particles.

Paramecium: Paramecium either undergoes photosynthesis or catches food by predation.

Locomotion

Euglena: Euglena uses a flagellum for its propagation.

Paramecium: Paramecium uses cilia for its propagation.

Sense

Euglena: Euglena is sensitive to light.

Paramecium: Paramecium is sensitive to temperature, light, chemicals, as well as touch.

Reproduction

Euglena: Euglena only undergoes asexual reproduction.

Paramecium: Paramecium undergoes both sexual and asexual reproduction.

Conclusion

Euglena and Paramecium are unicellular, aquatic microorganisms that belong to the kingdom Protista. Euglena consists of chloroplasts. However, they ingest food particles as well. Paramecium lacks its own chloroplasts. But, it swallows green algae. Paramecium also catches food as a predator. For locomotion, Euglena uses flagella while Paramecium uses cilia. The main difference between Euglena and Paramecium is their mode of nutrition.

Reference:

1. “What’s Euglena?”, .euglena.it, Available here.
2. Vidyasagar, Aparna. “What Is a Paramecium?” LiveScience, Purch, 23 June 2016, Available here.

Image Courtesy:

1. “Euglena diagram” By Claudio Miklos – Simple English Wikipedia (CC0) via Commons Wikimedia
2. “Ciliate” By Ali Zifan – Own work (CC BY-SA 4.0) via Commons Wikimedia