5 differences between zooplankton and phytoplankton

In the aquatic environmentss we can find a large number of organisms, from microscopic to animals of hundreds of tons. One of the most captivating animal groups is plankton. Plankton are those microscopic organisms that live in suspended or floating bodies of water, fresh or marine.

Within them you can distinguish two groups of animals: the phytoplankton, which performs photosynthesis, and the zooplakton, which feeds on other organisms or debris. But this is not the only difference. In this lesson from a TEACHER we will see the main differences between zooplankton and phytoplankton with examples of both groups.

The plankton are those microscopic organisms that live suspended or floating bodies of water, sweet or marine. These organisms are able to move, but they do not swim and therefore cannot resist currents or turbulence in the water. The plankton remains in the water currents, which are responsible for passively moving them from one side to the other.

Within the plankton we can find two groups, depending on the method used to obtain energy and organic matter:

• Phytoplankton: are the organisms that make up plankton and perform the photosynthesisIn other words, they are capable of producing the energy they need from sunlight and nutrients from the water. They are autotrophic organisms and are important primary producers in aquatic environments.
• Zooplacton: are the heterotrophic organisms that they are part of the plankton. These animals obtain their energy by consuming other organisms or their waste (detritus).

Thanks to their photosynthetic capacity, phytoplankton organisms found in waters with a large amount of nutrients (organic matter) can grow uncontrollably. This uncontrolled reproduction of phytoplankton leads to the so-called eutrophication of the waters, a very common process by which the waters become dark and with little oxygen since everything is consumed by these organisms. They are contaminated waters and are not very valid for the life of zooplankton and other organisms of the trophic chain, including humans.

Despite being included within the same group, there are numerous disparities between zooplankton and phytoplankton, differences that range from their position within the ecosystem to the size of their body. Here are 5 main differences between phytoplankton and zooplankton:

1. Size of your body. Phytoplankton are made up of small organisms: hopefully they are only a few millimeters long, although most are invisible to the naked eye. On the other hand, the organisms that make up the zooplakton can be larger: it ranges from the larvae of clams, crustaceans, fish and echinoderms to larger individuals such as jellyfish.
2. Place in the food chain. Phytoplankton make up an important part of the primary producers of the sea, while zooplakton occupy a position intermediate between phytoplankton and higher trophic levels, among which many species of pelagic fish stand out, such as sardines or anchovy.
3. Effects of the increase in its population. The controlled increase of the population of organisms of the phytoplankton would produce an increase of the amount of oxygen and food available for the zooplankton. This means that, indirectly, an increase in phytoplankton also produces an increase in zooplacnton. On the other hand, an increase in the number of zooplankton organisms produces greater predation on the phytoplankton and, therefore, a decrease in the number of phytoplankton individuals. An uncontrolled increase in the phytoplankton population causes, as we have commented before, the eutrophication of the waters.
4. Ability to generate oxygen. Being photosynthetic organisms, phytoplankton organisms are capable of producing and releasing oxygen to the aquatic environment while zooplanktonic organisms do not have the capacity to generate oxygen.
5. Role as environmental indicators. Phytoplankton organisms depend to a great extent on environmental conditions, therefore, they are generally used to assess and monitor the "health status" or stability of aquatic environments (especially marine). On the other hand, zooplanktonic organisms are affected by more determinants and are usually studied to evaluate the toxicity of compounds in the sea or the contamination in them.

Phytoplankton are mostly made up of cyanobacteria, cyanophyceae and chlorophyceae, diatoms, and dinoflagellates. Some econcrete examples of species of phytoplankton organisms They are:

• Chlorella vulgaris
• Chlamydomonas spp.
• Eudorina elegance
• Clostridium spp
• Chlosterium spp.
• Ankistrodesmus falcatus
• Scenedesmus spp.
• Pediastrum duplex
• Navicula spp.
• Merismopoedia spp.
• Peridinium spp
• Ceratium spp.
• Diatom spp.

The species that make up zooplankton are tremendously varied. The main components of zooplankton are small crustaceans such as copepods and cladocerans but there are also organisms representing the phylum of rotifers.

Some of the zooplanktonic animal species best known are:

• Cephalodella spp
• Lecane spp
• Rotaria spp
• Philodinacus paradoxus
• Daphinia longispina
• Ceriodaphnia spp
• Tropocyclops pracinus
• Cyclops vicinus
• Eucyclops serrulatus
• Erythraeus acetes
• Acetes intermedius
• Lucifer penicillifer
• Acartia erythaea