that floating in the water column



plankton, which in Greek means "wandering" - a collection of marine organisms floating in the water and unable to resist the currents.Most of the members of a given population - a very tiny plants and animals - diatoms and some other algae, bacteria, protozoa, crustaceans, molluscs and coelenterates, eggs and fish larvae, the larvae of invertebrates.But also among the passively floating there, and quite large objects - huge seaweed, giant jellyfish, and even some fish, such as sunfish, weighing up to two tons, but which it prefers not to be moved by applying muscular effort, and soar inwater column or on the surface.Previously, such large flora and fauna attributed to a s
eparate category - macroplankton.

Plankton is of great importance for marine life, as is the food most of the species, directly or indirectly through the food chain.

Classification



There are several classifications of organisms that make up the plankton.Scientists divide its inhabitants, depending on the species.So, there is the phytoplankton, zooplankton and ichthyoplankton.Under phytoplankton means that part of free-floating organisms that is capable of photosynthesis.These are diatoms, dinoflagellates and other unicellular algae and cyanobacteria.It is the excessive multiplication of phytoplankton is the phenomenon of algal blooms.

Zooplankton is unable to withstand the current set of animals.These include heterotrophic protists, small crustaceans.The main part of the diet of zooplankton, phytoplankton, as well as their smaller counterparts.There are a special kind of zooplankton - ichthyoplankton.He was treated fish eggs and larvae, as well as the fish themselves navigating solely by the will of the current.

Depending on the lifestyle divide on plankton and holoplankton meroplankton.Representatives of the first-class spend their entire lives, hovering in the water column.By meroplankton are those organisms for which this way of life is only an intermediate step.These are the larvae and fish eggs and multicellular invertebrates, as well as representatives of some algae.As the meroplankton either settles to the bottom and begins to near the bottom, or proceed to active swimming.