What is zooplankton

Zooplankton, or animal plankton , is the term that receives the set of all and those living organisms belonging to the Animal Kingdom that float errantly within the first 200 meters of depth of many of the aquatic ecosystems of the planet.

These animals that make up zooplankton are usually mainly microscopic in size, and, together with phytoplankton or plant plankton , fill the fresh and salty waters of aquatic ecosystems with suspended life. Let’s see in the following list more characteristics of zooplankton :

• The organisms that make up zooplankton are heterotrophic , feeding on primary producers such as phytoplankton, as well as other animal components of zooplankton, and other microorganisms in suspension, such as decomposing bacteria and organic waste.
• They have high growth rates and short life spans.
• Zooplankton is considered one of the essential components of the biological communities of aquatic systems, occupying the position of primary consumer in the trophic chains and being the link that unites the autotrophic organisms of producers (phytoplankton) with secondary consumers (fish, marine mammals, some birds and all kinds of invertebrates).
• Zooplankton is present both in open sea aquatic ecosystems (seas and oceans of the world), and in freshwater lentic ecosystems (lakes, lagoons, etc.).

As we have mentioned before, the animals that are part of zooplankton are mainly microscopic organisms, so many of them can be great unknown if we are not familiar with the taxonomic groups of invertebrate animals. Krill ( Meganyctiphanes norvegica) is probably the best known zooplankton animal, but what about the other animals that compose it? In the following list of examples of zooplankton you can learn the name of many of them:

• Copepods.
• Cladoceros.
• Rotifers.
• Ctenophores.
• Siphon.
• Pelagic polychaetes.
• Ostrácodos.
• Echinoderm larvae.
• Crustaceans small, such as decapod, and their larvae nauplio type characteristics.
• Eggs, larvae and juveniles of some species of fish.

As a component of the trophic chains of aquatic ecosystems , the presence of zooplankton is essential for the correct functioning and optimal balance of these ecosystems. According to the specific composition and vital characteristics of said zooplankton, it is possible to know the state of well-being or, on the contrary, the deficiencies of the aquatic biological systems and communities, so we can affirm that zooplankton is an optimal indicator of quality of the aquatic ecosystems .

In addition, zooplankton plays a very important role within planktonic interactions, that is, in the biological relationships that occur between organisms that are part of the zooplankton-phytoplankton, as well as within the zooplankton itself.

On the other hand, the amazing biodiversity that characterizes the composition of zooplankton is considered one of the most important natural resources of aquatic ecosystems, since they guarantee the upwelling of nutrients and animals from other links in the trophic chain during such important natural phenomena. like, for example, El Niño.

As we have seen previously, both zooplankton and phytoplankton are part of the planktonic communities that serve as food for many animals, thus maintaining the balance of the trophic chains of aquatic ecosystems. However, there are several differences between the two groups of aquatic organisms. These are the main differences between zooplankton and phytoplankton:

• As their own names indicate, zooplankton is made up of animal species, while phytoplankton is made up of plant species.
• They are heterotrophic and autotrophic organisms , respectively.
• Zooplankton is distributed at any depth within the first 200 meters of open ocean ecosystems, while phytoplankton are found only in the highest layers, those that receive sunlight.

To finish knowing these organisms, we recommend you read these other AgroCorrn articles on What is phytoplankton and What is plankton and its importance .

If you want to read more articles similar to What is zooplankton , we recommend that you enter our Biodiversity category .