Amoeboid protozoans: Characteristics, Different Forms, Diagram

Amoeboid protozoan resembles amoeba due to the presence of pseudopodia in it. Amoeboid is a type of unicellular microorganism that has the ability to change its shape by extending and retracting pseudopods. Amoeboids move and capture their prey by putting out pseudopodia which are also known to be their false feet as in Amoeba. Amoeboid protozoans lack periplast in their body so they are usually covered in calcareous shells and have temporary pseudopodia which help them in capturing the prey. Amoeboid protozoans cannot make their own food so are dependent on others for food.

Keyterms: Amoeba, Unicellular Microorganism, Protozoan, Holozoic nutrition, Entamoeba histolytica

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Amoeboid Protozoan

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Amoeboid protozoan likes to stay in aquatic or moist habitats. Amoeboid protozoans can be predators as well as parasitic. Amoeboid protozoan has holozoic nutrition. They are ubiquitous and are found everywhere. 

• They are present in all aquatic or moist environments, and their cysts can be found in even the most inhospitable parts of the biosphere. 
• There are many protozoa that cause various diseases in animals and humans such as malaria parasite, sleeping sickness, trichomoniasis, etc.

Example: Some of them such as Pelomyxa, Radiolarians, Heliozoans, and Foraminifera, and Entamoeba histolytica, Arcella, Difflugia, etc are some of the freshwater shell amoeboids. Marine form amoebas have silica shells on their surface.

Amoeboid Protozoan

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Important Facts About Amoeboid Protozoan

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The important facts about amoeboid protozoan are given below:

• Amoeboid protozoans are naked. They have no test oil shell.
• They can change their shape whenever they want.
• They use their pseudopodia to capture food.
• They are usually covered in calcareous shells.
• All the free-living amoebae are particle feeders.
• Sexual reproduction is not present in them.

Important Parts of Amoeboid protozoans

Also Read- Autotrophic Bacteria

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Characteristics Of Amoeboid Protozoan

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Some of the characteristics of amoeboid protozoan are:

• Amoeboid protozoans are mostly free-living, found in freshwater, seawater, and on damp soil. Only a few are parasitic.
• Their body is covered with plasma or a shell.
• Amoeboid protozoans are found in the aquatic environment. They live in freshwater or oceans.
• In Amoeboid Protozoan sexual reproduction occurs through syngamy.
• In Amoeboid Protozoan asexual reproduction takes place by binary fission, multiple fission, budding, and spores.
• Amoeboid Protozoans develop pseudopodia which are temporary protoplasmic outgrowths.
• Some amoeboid protozoans are free-living but some are parasitic and live attached to plants and animals.
• The life cycle of most of the amoeboid protozoan alternates between the dormant cyst stage and proliferating vegetative stage
• Sarcodines are generally uninucleate. Bi-nucleate (e.g., Arcella) and multinucleate (e.g., Pelomyxa) types also occur but the nuclei are monomorphic
• Nutrition is commonly holozoic.
• Pseudopodia in an amoeboid protozoan are used for locomotion and engulfing food articles.

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Different Forms Of Pseudopodia In Amoeboid Protozoan

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Amoeboid protozoan’s body lacks a Periplast. Therefore, they have temporary protoplasmic outgrowths called pseudopodia or a false foot which helps in movement and capturing prey. And some of the different forms of pseudopodia are:

1. Lobopodia- Lobopodia which is also known as little foot is the broad cell process containing ectoplasm and endoplasm. Lobopodia are used for locomotion and engulfing their food.
2. Filopodia- Filopodia which is also known to be thread contains only ectoplasm. Filopodia provide a constant two-way streaming movement that delivers food in a conveyor belt.
3. Reticulopodia- Reticulopodia or which is also known to have a netlike structure is similar to filopodia but they are branched and rejoin to form a netlike series of cell extensions.
4. Axpodia- Axpodia which is also called axle is a thin layer filamentous which are supported by a central axis of microtubules. The cytoplasms covering the central axis are adhesive and are movable.

Different Types of pseudopodia in Amoeboid Protozoan

Also Read- Creutzfeldt Jakob Disease 

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Diagram of Amoeboid Protozoan

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Here is a diagram of amoeboid Protozoan-

Diagram Of Amoeboid Protozoan

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Things to Remember

• Amoeboid protozoans can be described as a group of protozoans, which can be defined by their amoeboid movements.
• Their body lacks a Periplast.
• These kinds of protozoans are mostly free-living, found in freshwater, seawater, and on damp soil.
• Some of these protozoans are parasites.
• There are different types of Pseudopodia In Amoeboid Protozoan. For example- Lobopodia, Filopodia, Reticulopodia, axpodia.