Habitat organisms are constantly exposed to various changing factors.Organisms capable reflects the parameters of the environment.In the course of the historical development of living organisms they have mastered the three habitats.Water - the first of them.In her life originated and evolved for millions of years.Ground-based Air - the second environment in which animals and plants have emerged and adapted.Gradually transforming the lithosphere, which is the top layer of the land, they created the soil, which became the third habitat.
Each type of fish that live in a particular environment, characterized by its own type of energy and metabolism, the preservation of which is important for normal development.When environmental conditions that threaten the body imbalance of the exchange of energy and matter, the body, or changes its position in space, or translates itself in better conditions, or changes the activity of exchange.
aquatic habitats
Not all factors play an equivalent role in the life of aquatic organisms.According to this principle can be divided into primary and secondary.The most important of them - it's mechanical and dynamic characteristics of the bottom soil and water, temperature, light, suspended and dissolved substances in the water and others.
Factors aquatic
aquatic habitats, called the hydrosphere, takes up 71% of the entire planet.The water volume of nearly 1.46 billion. Cube.km.Of these, 95% - it is the oceans.Fresh water is composed of glacial (85%) and underground (14%).Lakes, ponds, reservoirs, marshes, rivers and streams occupy a little more than 0.6% of the total amount of fresh water, 0.35% is contained in the soil moisture and atmospheric vapor.
aquatic habitats inhabited by 150 thousand animal species (and this 7% of all living creatures of the Earth) and 10 thousand plant species (8%).
near the equator and tropical zones of the world of animals and plants, the most diverse.If you delete these zones in northern and southern direction of the qualitative composition of aquatic organisms is becoming poorer.The organisms of the oceans are concentrated primarily off the coast.Life is practically absent in the open waters located far from the coast.
Water Properties
determine the physical properties of water vital activity of living organisms in it.Among them, especially important thermal properties.These include a large heat capacity, low thermal conductivity, high latent heat of evaporation and melting, expansion of the property before freezing.
Water - excellent solvent.The dissolved state all consumers absorb inorganic and organic substances.Aquatic habitat helps transport substances inside organisms decay products also stand out with water.
high surface tension of water is retained on the surface of the animate and inanimate objects and fills the capillaries, thereby feed on terrestrial plants.
Transparency promotes photosynthesis of water at great depths.
Environmental groups aquatic organisms
- Bentos - these organisms, which are attached to the ground, lying on it or live in the thick sediments (phytobenthos, zoobenthos and Bakteriobentos).
- Periphyton - animals and plants that are attached or held for the stems and leaves of plants, or for any surface, towering above the bottom and floating down the river water.
- Plankton - free-floating plant or animal organisms.
- Nekton - actively swimming organisms with a sleek body, not connected with the bottom (squid, fish, whales, pinnipeds, etc.).
- Neuston - microorganisms, plants and animals that live near the surface of the water between the water and air environments.This bacteria, protozoa, algae, larvae.
- pleustonic - aquatic life, partly in the water and partly over its surface.It sailboats siphonophores, duckweed and arthropods.
Dwellers Rivers called potamobiontami.
aquatic habitat is characterized by the peculiar conditions of life.The distribution of organisms are strongly influenced by temperature, light, water flow, pressure, dissolved gases and salts.Living conditions in marine and inland waters are very different.Sea water is a more favorable environment, close to the saline.Continental water for their residents are less favorable.
