Migration is one of the most complex forms of behavior of animals - birds and fish - which can be regarded as hereditary adaptations specific to the species and with other properties determine the characteristics of the species, subspecies, or population that intraspecific biological form.
At the sturgeons, migration is a very importantăa feature ontogenesis, the life cycle, and allows to use all the possibilities presented by the complete area of distribution. It has an integrated system of primary pro interadaptaţiilor system that led to success vietuirii million years within these is the "gold fish" as sturgeon are also known in the world, due to their special value.
Sturgeon migration in our waters, as in the other basins of the world, efectueazăpe long distances, such bazinului.De bottom stor sturgeon move tens of miles, hundreds of miles sturgeon or beluga, which exceeds one thousand kilometers of Black Sea, the river Danube to repreducere natural areas. After submission of mature sexual elements - eggs and milk - are on the same road reântorc close to the surface water in places where they went. Breeding in natural areas after sturgeon larvae have hatched, do a migration stream water pasivape larvae gradually becoming chicken. In the Black Sea after 1-2 months when they reach an average weight of 2-3 g / sample.
The vast majority of species, subspecies and forms of organic or biological forms of sturgeon intraspecific life is characterized by addition migratoare.În starlet and cover our waters, the Kaluga of Amur sturgeon lake anerican and other species that are only some local deplsări all other marine species are migratory. The exception also includes some forms of biological freshwater sturgeon, chicken living in the state of the marine environment or oceanicdar only to fall only in the river reproducare dulcicol.
In most cases, migration is related to changes sturgeon considerable environmental osmotic pressure of salt water crossing the sea or ocean, in fresh water and vice versa fluviilio and therefore are related to control mechanisms osmotica.Această rconstituirea essential condition of behavior sturgeon may occur in certain seasons and therefore in different environmental conditions of different ages and stages exteriorla wide variety of different sexual glands and the degree of fattening. in determining migrations have an important role sex hormones in the blood of fish entering the car some etepe life cycle and carecterul "the pituitary gonadotropins," but without being the only factors are added migratiei.La migratiilior body, migration season, hydrological and hydrobiological conditions of the river for each form of intraspecific biological 'spring' and autumn. Outer environment is particularly migration from one species to another and from one form to another biological.
Sturgeon migrations are one of the most important adaptations that contribute to widening and increasing Areli special fund, which lead to her biological progress. Contriluie migrations to specific differences between and within populations to the formation of races of the season ecoforme, development of ecological potamodrome.Deosebirile euribiforme and occur mostly in the different behavior during migration.
Endocrine system is the main link between natural cyclical phenomena and achieve successive phases of ontogenesis sturgeon. Increased activity-pituitary and endocrine hipothalamo devices, which then determines migration paremerg be installed due to the action of some excited flags of the external environment, in fact cyclical phenomena of these fish.
The presence of a complex structure and varied in terms of population or species ecological sturgeon is a prerequisite for transformation microevolution, which are biological macrodiferenţieri time as I mentioned.
Obstacles to migration of sturgeon is increasing on the one hand due to river pollution in certain areas of waste water discharge or unused, from insufficiently treated industrial combined important, on the other hand, due to hydropower constructions on the river whose basin are locuru naturake of reprodocere. To remove these two negative factors for natural reproduction of sturgeon were enacted measures to wastewater treatment in our country and be done with construction construction hidroenegretice for downstream migratory fish passage upstream of hydroelectric power, as they conducted in Volgograd.
The first experiments of artificial fertilization caviar Ovseanikov link to his name, who performed in 1869 in Russia, the artificial fertilization of sterlet eggs, incubate them and obtained larvae.
Besides Ovseanikov Kovalskii and Wagner in 1870 published the results rebuke starlet development. These surveys were completed by Zelenskii.
And sevruga sturgeon species, the first fertilization experiments were made during 1884-1889 by Bordoin, and ended with obtaining important Cantiere larvae. Bordoin's Experinnţele were made with some breeding Ural river fishing, in their last stage of maturation. Experiences repreducători sturgeon caught in the wild and park in different types of juvelnice have taken Ber and Borodin, but have not obtained sexual elements mature.