Sea world is amazing and diverse. It occurs as huge animals, reaching a length of several tens of meters, and weighing hundreds of tons, and very tiny organisms.
Some of them are actively paving their way through the water column, while others are quietly swimming along the current.
They are called plankton.
What floats in the water column
Plankton, which in Greek means"Wandering" is a collection of marine organisms floating in waters and unable to resist currents. Most of the members of this population are very tiny plants and animals - diatoms and some other species of algae, bacteria, protozoa, crustaceans, coelenterates and mollusks, eggs and larvae of fish, invertebrate larvae. However, also among the passively floating there are also quite large objects - huge algae, giant jellyfish and even some fish, for example, a fish-moon, whose weight reaches two tons, but which prefers not to move, applying muscle effort, but to soar in Thicker than water or on the surface. Previously, such large representatives of flora and fauna were classified as a separate category - macroplankton.
Plankton is of great importance for marine life, since it serves as food for most animal species, directly or through links in the food chain.
There are several classifications of organisms,Which are part of the plankton. Scientists share its inhabitants depending on the species belonging. So, there is a phytoplankton, zooplankton and ichthyoplankton. By phytoplankton is meant that part of free-floating organisms that is capable of carrying out photosynthesis. Such are diatom algae, dinoflagellates and other unicellular algae, as well as cyanobacteria. It is the excessive reproduction of phytoplankton that causes such a phenomenon as the flowering of water.
Zooplankton is a collection ofUnable to resist the flow of animals. This includes heterotrophic protists, small crustaceans. The main part of the diet of zooplankton is phytoplankton, as well as its smaller counterparts. There is a particular type of zooplankton - ichthyoplankton. To it carry caviar and larvae of fishes, and also the fishes swimming exclusively at will of a current.
Depending on their lifestyle, plankton is divided intoHoloplankton and meroplankton. Representatives of the first class spend their entire life hovering in the water column. To meroplankton are those organisms for which such a way of life is only an intermediate stage. These are the larvae and caviar of fish and multicellular invertebrates, as well as representatives of some algae. As the growth of meroplankton either settles to the bottom and begins to lead a bottom-line lifestyle, or proceeds to active swimming.