Phylum Euglenophyta.

Phylum Euglenophyta

Characteristics

1. They are aquatic i.e. some are fresh water, some are marine and some species live in moist soil. Most members of the phylum have chloroplast and thus carry out autotrophic mode of nutrition though a few members are colorless and live in rectum of frogs.
2. All members possess flagella as a locomotory organelle and therefore are active swimmers.
3. Members of the phylum have pellicle which maintains the shape of the body although they can change their shape as they move about i.e. euglenoid movement.
4. All have myonemes (sort of muscles) which are contractile.
5. They store carbohydrate in form of paramylum. Paramylum gives a negative test with iodine.
6. They possess vacuoles and gullet.
7. They are sensitive to light i.e. they have photoreceptors stigmas.
8. They chiefly respire aerobically and a few species living in the rectum of frogs can respire anaerobically.
9. Under unfavorable condition they can form cyst which is tough and made of cellulose.

Characteristics of Euglena which make it a plant

1. They possess chloroplast with chlorophyll A and B therefore they are autotrophic.
2. They have the ability to utilize nitrates and ammonia for nitrogen requirements i.e. use of nitrates to make their proteins.
3. Possess paramanoids which are the form of stored protein.
4. Storage of carbohydrates in form of paramylum.
5. Presence of contractile vacuole.

Characteristics of Euglena which make it an animal

1. Presence of pellicles for support in the body.
2. Possess flagella which enable it to move actively (euglenoid movement).
3. They utilize amino acids and polypeptides as source of nitrogen.
4. Ability to form cysts during unfavorable conditions.
5. Possess myonemes which are contractile like muscles.
6. Possess gullet, sphincter.
7. Have a reservoir.
8. Possess eye spot and stigma as photoreceptor organelle.

Diagram of Euglena

Adaptations of Euglena to its mode of life

1. The body shape is elongated and oriented in such a way that allows them to be active swimmers.
2. The fresh water species possess contractile vacuole which excrete excess water. The marine species do not have contractile vacuole.
3. They possess chloroplast for photosynthesis i.e. autotrophic nutrition. But when the conditions are not favourable e.g. in the absence of light they feed saprophically.
4. Possess flagella for locomotion.