Nutrition in Protozoa

Nutrition in Protozoa- 

By Vidhin Kamble.  
Department of Zoology.  Sangola College, Sangola 

The of intake of food and used  for growth, metabolism are repair into the body is called nutrition. It involves ingestion, digestion, assimilation absorption, and excretion. Nutrition is necessary for survival of animals.

There are various kinds of modes of nutrition in protozoa, which are as follows.

1. Holozoic or Zoo-Trophic Nutrition

2. Pinocytosis

3. Autotrophic or Holophytic Nutrition

4. Saprozoic Nutrition

5. Parasitic Nutrition

6. Coprozoic Nutrition

7. Mixotrophic Nutrition.

1. Holozoic or Zoo-Trophic Nutrition:

Majority of Protozoa are holozoic in feeding habit like animals feeding upon on solid food. In this type, the food consists of microorganisms like bacteria, diatoms, rotifers, crustacean larvae, algae, small trashes of large animals, other protozoans and plants, etc.  This type of nutrition involves ingestion, digestion, assimilation, absorption and elimination or egestion of undigested food.

2. Pinocytosis: 

Pinocytosis is also called as  cell-drinking.  Pinocytosis found in protozoan such as  Amoeba proteus and certain flagellate and ciliates.

This type of mode of nutrition involves the ingestion of liquid food.

Some these protozoa pinocytic channels are developed from their outer surface due to invagination deep into the body. Toward the inner end of pinocytic channel pinocytic vesicles or pinosomes are present. these pinosome engulf liquid through the channel and get separate from the base of channel and becomes the food vacuoles.

3. Autotrophic or Holo-phytic Nutrition:

Some protozoan contains chlorophyll or some similar pigment in their cytoplasm. Because of this these protozoans are capable to synthesis of their own food as complex organic food like green plants, e.g., Euglena, Noctiluca.

4. Saprozoic Nutrition:

These protozoans are feeding upon dead or decaying organic matter. Some protozoa absorb liquid organic and inorganic substances by secreting enzymes, act upon decaying organic matter and break down into simple forms that are absorbed by organism.

Some protozoa absorb liquid organic and inorganic substance from surrounding through body wall by the process of osmosis called as osmotrophy. The saprozoic organisms require amino acid, ammonium salts, as nutrient.

Ex. Some protozoa ,Bacteria and fungi.

5. Parasitic Nutrition:

These are organism nothing but the parasitic forms feed either holozoically or saprozoically.

1.     Food-robbers:

These are the parasitic protozoan feeding upon digested and undigested food of their host. These parasitic forms are known as food robbers. Eg. Some ciliate such as Nyctotherus and balantidium 

2.     Pathogenic:

These are the  protozoan act as parasite feeding upon the living tissue of host causing harm to their host.

  

 6. CoprozoicNutrition:

These are the protozoans feeding upon faecal matter of the other organisms. Eg. Clamydophrys

7. Mixotrophic Nutrition:

Some protozoans are capable to feed themselves by more than one method. The best example of the mixotrophic nutrition are flagellates. They are autotrphic as well as zootrophic in feeding habit. e.g., Euglena