5 Phytoplankton Examples: That You Should Know

Phytoplankton is a small marine living algae which contain chlorophyll to produce food. It is a tiny marine living algae. They are autotrophic organisms they require sun light for production of food.

Phytoplankton lives on upper surface of water and usually float in water.

  • Protist
  • Cyanobacteria
  • Silica-encased diatoms
  • Dino flagellates
  • Green algae
  • Chalk- coated coccolithophores


Protist are the unicellular eukaryotic organisms. They are closely related to animals or plants in morphological and physiological characters.

But it is neither animal nor plant and fungus. Protists contain nuclear membrane around their DNA and also contain membrane bound cell organelles like chloroplast. These are usually motile aquatic organisms.

They may reproduce both sexually or asexually. In these organisms basically cell wall is absent but sometimes can be found. They have many ecological benefits in food web like as primary producers, as direct food sources, and as decomposers.

Most of protists may cause diseases in humans as well as in plants.

The size of protists maybe minute (microscopic) to several meters.

Phytoplankton examples
Image Credit: Protist Wikipedia


Cyanobacteria can be also known as cyanophyta. They come under kingdom monera. These are gram negative, aerobic bacteria that can produce food through photosynthesis.

These the aquatic organisms mostly found in fresh water. These organisms are unicellular or multicellular. They contain filament and the colonies are formed on the surface of the water. The size may range from 0.5 to 60 micrometres.

They can infect humans by producing toxins. They can also affect the life cycle of other organisms as they consume more oxygen and nutrients which are used for others.

The toxins of cyanobacteria can cause gastro intestinal problems, hay fever, skin rashes and respiratory problems.

These can be referred as primary producers of the food chain as they produce their own food.

Image Credit: Cyanobacteria Wikipedia

Silica-encased diatoms:

These are generally known as micro algae and can be found in the oceans, soil. They generally form earth biomass and can produce 20-50 percent of oxygen on the earth every year.

These are usually unicellular organisms. They occur in single cells or in colonies. In colonies they may take the shape of the ribbons, fans, zigzags, or stars.

In the suitable environment they can reproduce for 24 hours through asexual reproduction.

The cell wall is comprised of silica. This is transparent in nature. They are autotrophic in nature. They have the ability of converting light energy into chemical energy which is aided by pigments like chlorophyll and carotenoids.

Dino flagellates:

These are the unicellular protists. They possess two flagella. Some species are photosynthetic and form major class of eukaryotic algae. Some species can be heterotrophic in nature and get food through phagocytosis. They can share the features with both plants and animals. They can be parasitic and endosymbiont for red algae. They may be red, green, yellow, or brown depending on the pigments. They reproduce commonly through asexual reproduction. They contain urea cycle.

The cell is covered with the coat called amphiesma, it contains flattened vesicles. Flattened vesicles can be referred  as alveoli which can be seen inside the plasma membrane. The nucleus of dinoflagellate is known as dinokaryon.

If there is a sudden population increase, it may lead to red tide. Red tide means that the colour of water is changed to red colour due to toxins released by the dino flagellates. The toxins may cause the death of fish and can also affect the humans through fish.

Green algae:

Greenalgae includes the prasinodermophyta. They may be unicellular or colonial flagellates.

Theyare macroscopic and multicellular sea weeds. Some other organisms depend on green algae for photosynthesis process as they contain chloroplast.

The main pigments in green algae are chlorophyll a and b and the thylakoids contain beta carotene and xanthophylls in stackes.

The main component of cell wall is cellulose and they store carbohydrates in polysaccharide form like starch.

Flagella can be seen in male gametophytes.

Chalk- coated coccolithophores:

The main component of them is calcium corbonate. The size may range from 5-100 micrometers.They perform photosynthesis. The chloroplast is in brown colour.

These are produced during biomineralization process. The calcium is produced in the golgi complex. They play crucial role in the marine carbon cycle.

They form calcite skeletons in the surface layer and later sink into deep layer of water through this process they maintain the alkalinity of sea water.

These can be referred as golden algae.


Thus the phytoplankton play a pivotal role in oxygen production through photosynthesis process and can also maintain the food chain.

Narne Naga Srilakshmi

Hi All, Myself Narne Naga Srilakshmi. I have done Post Graduation in Bio-Technology also completed B.Ed. I always have a passion for writing and teaching. I assure my articles will help readers to understand difficult topics in simple way.

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