Difference Between Phytoplankton and Zooplankton

Main Difference – Phytoplankton vs Zooplankton

Phytoplankton and zooplankton are two types of planktons or organisms that drift along the surfaces of water. Both phytoplankton and zooplankton are similar in size and their ecological importance. The main difference between phytoplankton and zooplankton is that phytoplankton is a plant-like organism whereas zooplankton is an animal-like organism. Phytoplankton serves as a primary producer in the aquatic food chains. It produces food either by photosynthesis or chemosynthesis. Phytoplankton releases a lot of oxygen through photosynthesis. Phytoplankton is also a good indicator of ocean health. Any changes in the conditions of the ocean may change the growth of the phytoplankton. Zooplankton eats phytoplankton.

Key Areas Covered

1. What is Phytoplankton
      – Definition, Features, Role
2. What is Zooplankton
      – Definition, Features, Role
3. What are the Similarities Between Phytoplankton and Zooplankton
      – Outline of Common Features
4. What is the Difference Between Phytoplankton and Zooplankton
      – Comparison of Key Differences

Key Terms: Autotrophs, Copepods, Chemosynthesis, Diatoms, Dinoflagellates, Heterotrophs, Holoplankton, Meroplankton, Photosynthesis, Phytoplankton, Zooplankton

What is Phytoplankton

Phytoplanktons are a type of autotrophic planktons. Phytoplanktons are commonly called microalgae. Phytoplankton can be either photosynthetic or chemosynthetic. Phytoplankton is one of the primary producers of the aquatic food chains. Phytoplankton can be found in both marine and fresh water habitats. The photosynthetic phytoplankton grows in the upper sunlight layer of water bodies. The chemosynthetic phytoplankton can be found in deep sections of the water body where no sunlight can pass through.

Figure 1: Phytoplankton

The two major types of phytoplankton are diatoms and dinoflagellates. The shape of a diatom can be a sphere, ellipse or star. The significance of the diatoms is the silica shell, which serves as the cell wall of diatoms. Most dinoflagellates comprise a pair of flagella for the movement. Moreover, the oils in the body of both diatoms and dinoflagellates help the movement through water. The high growth rates of diatoms and dinoflagellates cause algae blooms. The red tide is a type of a marine algae bloom which produces biotoxins. These biotoxins can harm small fish.

What is Zooplankton

A zooplankton is a common name for many microscopic animal forms, which can be found in both fresh and marine water habitats. Zooplankton drift or float in the middle layer of water bodies. The zooplankton is a heterotrophic organism that consumes phytoplankton, another zooplankton or detritus. Therefore, zooplankton can be a primary or secondary consumer of an aquatic food chain.

Figure 2: Several Types of Zooplankton

The two major types of zooplankton are holoplankton or meroplankton. Holoplankton remains as a plankton throughout its lifecycle while meroplankton is a larval stage of another life form. Copepods are another type of zooplankton. They are a group of crustaceans. Copepods possess spikes which aid their movement through water. The filter-feeding organisms such as whales, fish, and shellfish eat zooplankton. Water temperature can also kill many of the zooplankton.

Similarities Between Phytoplankton and Zooplankton

• Phytoplankton and zooplankton are two types of plankton.
• Both phytoplankton and zooplankton are microscopic.
• Both phytoplankton and zooplankton can be found in fresh and marine water habitats.
• Both phytoplankton and zooplankton are sessile organisms.

Difference Between Phytoplankton and Zooplankton

Definition

Phytoplankton: Phytoplanktons are plant-like aquatic microorganisms.

Zooplankton: Zooplanktons are aquatic animal-like organisms and the larval stages of other life forms.

Examples

Phytoplankton: Diatoms, dinoflagellates, blue-green algae, and cyanobacteria are examples of phytoplankton.

Zooplankton: Crustaceans-like krill, holoplankton, meroplankton, protozoans, and worms are examples of zooplankton.

Morphology

Phytoplankton: Phytoplanktons are brown in color. Cloudy patches are formed when they grow as a group.

Zooplankton: Zooplanktons can be found in different colors and shapes, but are mostly translucent.

Found in

Phytoplankton: Phytoplanktons are found in the upper sunlight layer or the euphotic layer of the water body.

Zooplankton: Zooplankton is found in the deep sections of the water body.

Nutritional Mode

Phytoplankton: The phytoplankton is autotrophic.

Zooplankton: The zooplankton is heterotrophic.

Feeding

Phytoplankton: Phytoplankton produce their own food by photosynthesis or chemosynthesis.

Zooplankton: Zooplankton eat phytoplankton, other zooplankton or detritus.

In Aquatic Food Chains

Phytoplankton: Phytoplankton is the primary producers of the aquatic food chains.

Zooplankton: Zooplankton is the primary or secondary consumers of the aquatic food chains.

Release of Oxygen

Phytoplankton: Phytoplankton releases lots of oxygen.

Zooplankton: Zooplankton consumes oxygen.

Conclusion

Phytoplankton and zooplankton are the two types of planktons found in both fresh and marine water habitats. Phytoplankton is the plant form of the planktons whereas the zooplankton is the animal form. Phytoplanktons are one of the primary producers of aquatic food chains, which produce its food either by photosynthesis or chemosynthesis. Zooplankton is a heterotrophic organism, which eats phytoplankton, another zooplankton or detritus. The main difference between phytoplankton and zooplankton is their mode of nutrition.

Reference:

1.”What are phytoplankton?” NOAA’s National Ocean Service. N.p., 27 July 2009. Web. Available here. 09 Aug. 2017. 
2.”Zooplankton.” Environmental Data Center. University of Rhode Island., n.d. Web. Available here. 09 Aug. 2017.

Image Courtesy:

1. “1348508” (Public Domain) via Pixabay
2. “Zooplankton” By Matt Wilson/Jay Clark, NOAA NMFS AFSC. (Public Domain) via Commons Wikimedia