Lake is considered to be water retention, which is formed on the land in a natural recess.At the same time it is a closed basin.Comprising a natural formation of the bed, which is filled with water up to their edges.There are various types of lakes.There are tectonic and river basins, coastal and ice, and artificial crater, mountain and failing.This classification indicates their origin.
Features lakes
Unlike rivers natural bodies of water do not have currents.However, they do not belong to the oceans.Another distinctive feature is their different water salinity.Thus, the deepest lake is Lake Baikal.At the same time it is absolutely insipid.Amazing natural formation of a Caspian (see photo) lake.According to the composition of its salt water like the ocean.Previously, it was the Caspian Sea.Now it is a lake.Changes occurred after the loss of communication with the ocean.
Group the lake's water balance and posture, nutritionally contained in its water substances, as well as their composition.
particularly large.There are various lake bottom topography, as well as a variety of sizes and shapes.They are not only rainwater.They nourish and underground rivers.
the map Russia is more than two hundred thousand lakes.Among them is the biggest in the world - the Caspian.In Russia there is the deepest lake - Lake Baikal, and also the largest in Europe - Ladoga and Onega.
habitats
flora and fauna of the lakes has its own special character.Basically, natural ponds are home to a large number of representatives of freshwater species, as well as the few saltwater.
Organic population of the lake consists of the following components:
1. Plankton.It is a collection of small organisms which are passively transferred with water.
2. Bentos.This group includes organisms whose habitat is the soil or lake bottom.
3. Nekton.The organisms are included in this group are actively moving aquatic animals.
inhabitants of the lake, as a rule, are located in three main areas.The first - the littoral.This is an area that is completely covers the coastal zone.Second - profundalu.This deep-water area of the lake, which includes in its membership the bottom and adjacent to the aqueous layer.The third area is pelagic.It covers the rest of the water mass.
Flora
Lakes different zonal arrangement thickets of water and coastal plants.The nature of the flora changes with increasing depth.So, in the shallow zone is dominated by thickets of sedges.They are located no deeper than one meter from the water's edge.Here grows arrowhead and rushes, water, buckwheat and other wetland plants.
depth increases to two to three meters zone begins reeds.In this area grows a water horsetail, reed, as well as several other plant species.
Deeper still is a zone of flora with floating leaves.Here there are water lilies (water lilies), floating pondweed, and the capsule.At a depth of four to five meters is the area submerged plants.These include ezhegolovka and Urrutia and broadleaf pondweed.
What kind of fish live in the lake?
fauna is very diverse bodies of water.In the lake you can find almost all kinds of freshwater fish.The majority live there permanently.
What fish live in the lake?In the littoral zone found bleak and pike, perch and bullhead.There are fish that prefer to stay at depth.These include burbot and whitefish.This Russian inhabitants of the lake who live in the pelagic area.Some fish migrate periodically.For example, in the summer carp find food and shelter in the waters of the littoral zone.In winter, they descend into the middle layers of the lake.They are followed by predators.
division Lakers groups
delineates fauna reservoirs by the method of supply.The inhabitants of the lake, preferring to eat plankton - it smelt and whitefish, smelt and whitefish.In part, such fish include roach and ide and bream, perch and pike-perch (some over time turn into predators).The inhabitants of the lake with bottom feed - this chub and carp, crucian carp, bream and others.Air and coastal food prefer bleak and trout, roach and ide.These fish catch insects flying near the water surface or crawling from the water's edge.
Fauna and Flora Lakes Ladoga and Onega
rich and diverse natural world of the largest European lakes.They found about one hundred and twenty species of aquatic plants.Along the banks of reeds stretch.In the waters of the lakes are common blue-green algae.At the same time they number seventy-six species.The abundance of microorganisms (up to three hundred thousand per cubic centimeter) in the lakes allows the self-cleaning water.
rich in these water bodies and the world of freshwater fish.Here you can find salmon and Ladoga slingshot, roach and trout, catfish and smelt, rudd and roach, pike and burbot, and many others.
Baikal
In large lakes and shallow bays of flora and fauna does not differ from that which is characterized by small size fresh water.The mud lodge clams and snails.The water layers hunt pike and carp frolic.However, in areas where the water has a considerable size, the conditions change dramatically.For example, in some places the bottom of the lake lies at a distance of one and a half kilometers from the surface of its water surface.In such a deep lake has its own biological organisms.Communities living beings, who in the past have developed in this isolated realm of water, do not get outside of replenishment.Sojourn animal can get in the lake only against the current which flows into a river.And it is very few people under force.
inhabitants of Baikal
deepest lake in the world is home to five hundred species of plants and one thousand two hundred - animals.And almost eighty percent of them can be found only in the waters of Lake Baikal.They include large flat worms, with red and orange color, painted in stripes and speckles.It is found in the lake and fish, which can live on kilometer depth, as well as clams, which have very thin shells due to a lack of calcium in the water.
Baikal inhabit freshwater seal.This unique mammal, which has similarities to the Arctic ringed seal.
On Baikal freshwater has a population of tens of thousands of individuals.In the second half of winter animal schenitsya.At the same time it brings one or two cubs.The Baikal seal is an excellent diver able to dive to a depth of two hundred meters and stay there for up to twenty minutes.
Small animals
Baikal is home to the simplest single-celled organisms.Their meals are bacteria, microalgae.Multicellular invertebrates in Lake Baikal are divided into many species.The most famous of these is the Baikal epishura.These small crustaceans are inhabitants of the water column of the lake.This effectively clears epishura Baikal water your filter device consisting of hairs and bristles, which is located on the mouthparts.
rocky ground of the lake is a habitat for sponges.These are the exotic animals that inhabit zero.Still a colony of small invertebrates, microalgae are painted in various shades of green.Sometimes the shape of these colonies resembles sea coral.
At the bottom of Baikal bays and in the coastal shallows larvae fifty different species of caddis flies.Growing up, individuals leave the aquatic environment.
Fauna
What fish are found in Lake Baikal?Total found in its water fifty-two species.This number includes the Baikal omul.He is a member of the family of whitefish.Baikal omul fishing refers to fish and is the subject of sport fishing.It lives in the areas of underwater slopes that are at a depth of three hundred and fifty meters.
Even some fish in Lake Baikal is typical only for this water area?Among the unique inhabitants, there are two species belonging to the endemic family golomyankovyh (small and large golomyanka).They are fish of small size (length of a little more than twenty centimeters), who live at different depths of the lake and feed epishura and crustaceans.Golomyanka - food for the seals and Arctic cisco.
largest Baikal fish - a sturgeon.Not inferior to him in size and trout.Sturgeon, dwelling in the deepest lake, is listed in the Red Book of Russia.The duration of his life is fifty years.He is gaining weight to one hundred and thirty kilograms.The inhabitants of Lake Baikal - small fishes and bottom invertebrates - are the primary food for sturgeon.
