- What is phytoplankton?
- What do phytoplankton feed on?
- Importance of phytoplankton
- Phytoplankton and zooplankton
We explain what phytoplankton is and how this organism feeds. Also, why is it so important and what is zooplankton.
What is phytoplankton?
Let's start by defining plankton: an enormously diverse set of microscopic organisms that float in the fresh and salty waters of the planet, extremely abundant in the first 200 meters of depth of the waters and source of food of numerous species marine.
While plankton is made up of numerous forms of plant, animal, and protist life, it is traditionally classified into two: phytoplankton and zooplankton. The first is plankton autotroph, and the second the plankton heterotroph; that is, the first leads a nutritional life similar to plants, while the second leads a nutritional life similar to animals. This, of course, does not mean that they are strictly speaking plants Y animalsSo this classification, although accepted, is not entirely accurate.
Phytoplankton are mostly photosynthetic, so they proliferate in regions surface waters, where you have access to the sunlight and where there are the most abundant mineral salts (up to 30 meters deep). They are so numerous that they are responsible for the production of 50% of the molecular oxygen that allows and sustains life on Earth. In fact, many of the species that make up phytoplankton date back to the times of the Great Oxidation, the remote geological period in which the atmosphere he was filled with oxygen for the first time.
Broadly speaking, phytoplankton is composed of bacteria, cyanobacteria (blue-green algae), algae and especially diatoms, which are microscopic eukaryotic organisms with golden-yellow pigments.
In recent times, the levels of phytoplankton in rivers, lakes and oceans they have declined alarmingly, in principle due to the increase in the levels of ultraviolet radiation that filters through the atmosphere. In regions less protected by the ozone layer, the productivity of plankton has declined between 6% and 12%, which has called for alarm on the part of environmental sectors.
What do phytoplankton feed on?
Phytoplankton are autotrophic, that is, they make or synthesize their own food from non-organic sources, just like plants do. In fact, the photosynthesis It is its main metabolic activity, taking advantage of sunlight and water to manufacture useful biomolecules, releasing molecular oxygen in the process (O2).
Other species of phytoplankton carry out chemosynthetic processes, that is, the use of chemical energy generated by inorganic chemical reactions. In any case, we can say that phytoplankton feed on the inorganic material and external energy sources, from environment.
Importance of phytoplankton
These microscopic little creatures are the very basis of the food chain marine, as they provide food for microscopic organisms, fish, crustaceans and other kinds of underwater life, some as large as blue whales (which filter it from the water with their long bales). In that sense, they are producer organisms, which occupy the first link of the food pyramid.
On the other hand, phytoplankton is, as we said before, responsible for the highest oxygenation rate on the planet, producing as much or more of this molecular gas than plants themselves. That means that without them, the oxygen levels in the waters and in the air the atmosphere would descend, making the world a place less suitable for life as we understand it, and by making us depend even more on plants to manufacture the oxygen that animals breathe.
Phytoplankton and zooplankton
We have explained at the beginning the distinction between phytoplankton (autotrophs, producers) and zooplankton (heterotrophs, consumers), although these names would not be the most correct to differentiate them from a metabolic point of view. A second distinction would recognize holoplankton (organisms that are part of plankton throughout their lives) and meroplankton (organisms that only make up plankton during one stage of their life).
While phytoplankton could be understood as microscopic and photosynthetic aquatic beings, zooplankton would be a collection of diverse microscopic consumers, including parasites, larvae of larger organisms, eukaryotes unicellular and other life forms close to the animal kingdom.