Difference Between Phytoplankton and Zooplankton

Phytoplanktons are plants while zooplanktons are animals, this is the main difference between them. Other Crustaceans, krills are examples of zooplanktons; algae and diatoms are examples of phytoplanktons.

These two types of planktons float on water surfaces. Both are economically important and are similar in size. While phytoplanktons are a source of primary producers in the aquatic food chains, zooplanktons are consumers, it eats phytoplanktons. Phytoplanktons either produce food through chemosynthesis or photosynthesis. They are known to liberate large amounts of oxygen through photosynthesis and are deemed as good indicators of ocean health.

What Is Phytoplankton and Zooplankton?


  • Commonly known as microalgae, they are autotrophic planktons
  • They either can be chemosynthetic or photosynthetic
  • Can be found harbouring both freshwater habitats as well as marine habitats
  • Chemosynthetic phytoplanktons are found in deep sections of the water bodies wherein sunlight does not reach and photosynthetic phyoplanktons grow in the upper layer of water bodies where sunlight reaches
  • Dinoflagellates and diatoms are two main types of phytoplanktons


  • Found in both marine and freshwater habitats
  • Found floating in the middle layer of water bodies
  • They are heterotrophs consuming phytoplanktons hence they are primary or secondary consumers in the aquatic food chains
  • Two main types of zooplanktons are meroplankton and holoplankton

Difference Between Phytoplankton and Zooplankton

Following are some of the important differences between Phytoplankton and Zooplankton.




What are they?

Found in fresh and marine water, they are plant-like aquatic microbes

They are animal-like aquatic entities. Also, they are larval phases of other life forms


Blue-green algae, cyanobacteria, dinoflagellates, diatoms

Meroplankton, holoplankton, crustaceans such as krill, protozoans


Upper sunlight layer of the water bodies (euphotic)

Found in deeper ocean beds where sunlight does not reach


When they grow in a group, cloudy patches are formed, otherwise brown in color

Mostly translucent, can be found in varied shapes and colors


Lots of it liberated


Mode of nutrition

Through chemosynthesis or photosynthesis produces its own food

Consumes other zooplanktons and phytoplanktons

Position in the aquatic food chain

Primary producers

Primary or secondary consumers

These were some differences between phytoplanktons and zooplanktons. Watch this space at BYJU’S for more on NEET.

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