Jesiotr (Acipenser) Sturgeon
Jesiotr – Ta wspaniała ryba zamieszkiwała nasze wody, lecz
nie wytrzymała presji cywilizacji.W pamiętnikach marynarzy śródlądowych możemy
wyczytać, że jesiotry zamiast w lodówkach oczekiwały na zjedzenie żywe w wodzie
przywiązane łańcuchami do burt statków.
Jesiotr (Acipenser) Sturgeon
Jesiotr – Zamieszkuje wody przybrzeżne Adriatyku. skąd na tarło wkracza do rzek i potoków Niziny Padańskiej (Padu, Adygi i Tagliamento
Jesiotr – Największa ryba , która zamieszkiwała Polskie wody występowała w przybrzeżnych wodach Europy od wybrzeży Hiszpanii po północną część Norwegii ,w Morzu Północnym ,Bałtyku ,Morzu Śródziemnym i Morzu Czarnym , również wschodnie wybrzeża Ameryki Północnej. Długość ciała mogła przekraczać 4 metry a waga 300-400kg.To były okazy szkoda że na wolności nie doczekały naszych czasów
Jesiotr – Ryba wędrowna występująca w zlewiskach Morza Czarnego,Kaspijskiego i Azowskiego , osiąga ok. 130-150 cm długości i wagę ok. 20-30 kg. Trafiają się osobniki długości 3-4 m i wadze 150-200kg.
Jesiotr (Acipenser) Sturgeon
Sturgeon (Acipenser) is a genus of fish, of which twenty-one different species are known, from European, Asiatic and North American rivers. They are one of the oldest species of fish in existence. They pass a great part of the year in the sea, but periodically ascend large rivers, some in spring to deposit their spawn, others later in the season for some unknown purpose; only a few of the species are exclusively confined to fresh water. No species occur in the tropics or in the southern hemisphere. In Russia the fisheries are of immense value. Early in summer the fish migrate into the rivers or towards the shores of freshwater lakes in large shoals for breeding purposes. The ova are very small, and so numerous that one female has been calculated to produce about three million in one season. The ova of some species have been observed to hatch within a very few days after exclusion. Probably the growth of the young is very rapid, but we do not know how long the fry remain in fresh water before their first migration to the sea. After they have attained maturity their growth appears to be much slower, although continuing for many years. Frederick the Great placed a number of them in the Garder See Lake in Pomerania about 1780; some of these were found to be still alive in 1866. Professor von Baer also states, as the result of direct observations made in Russia, that the Hausen (Acipenser huso) attains to an age of 100 years, but can live over 200 years. Sturgeons ranging from 8 to 11 feet (2.5 to 3.5 m) in length are by no means scarce, and some species grow to a much larger size. The underside and mouth of a sturgeon Enlarge The underside and mouth of a sturgeon Sturgeon are bottom-feeders. With their projecting wedgeshaped snout they stir up the soft bottom, and by means of their sensitive barbels detect shells, crustaceans and small fish, on which they feed. Having no teeth, they are unable to seize larger prey. In countries like England, where few sturgeons are caught, the fish is consumed fresh, the flesh being firmer than that of ordinary fish, well flavoured, though somewhat oily. The sturgeon is included as a royal fish in an act of King Edward II, although it probably only rarely graces the royal table of the present period, or even that of the lord mayor of London, who can claim all sturgeons caught in the Thames above London Bridge. Where sturgeons are caught in large quantities, as on the rivers of southern Russia and on the great lakes of North America, their flesh is dried, smoked or salted. The ovaries, which are of large size, are prepared for caviar, for this purpose they are beaten with switches, and then pressed through sieves, leaving the membranous and fibrous tissues in the sieve, whilst the eggs are collected in a tub. The quantity of salt added to them before they are finally packed varies with the season, scarcely any being used at the beginning of winter. Finally, one of the best sorts of isinglass is manufactured from the airbladder. After it has been carefully removed from the body, it is washed in hot water, and cut open in its whole length, to separate the inner membrane, which has a soft consistency, and contains 70% of glutin. Sturgeon (and, therefore also the caviar trade) are under severe threat from overfishing, poaching and water pollution. The twenty-one species of sturgeons (Acipenser) are nearly equally divided between the Old and New Worlds. Most are now considered to be critically endangered, endangered or vulnerable. The more important are the following (from 1911 Encyclopædia Britannica): The common sturgeon of Europe (Acipenser sturio) occurs on all the coasts of Europe, but is absent in the Black Sea. Almost all the British specimens of sturgeon belong to this species; it crosses the Atlantic and is not rare on the coasts of North America. It reaches 12 ft (4 m) long, but is always caught singly or in pairs, so that it cannot be regarded as a fish of commercial importance. The form of its snout varies with age (as in the other species), being much more blunt and abbreviated in old than in young examples. There are 11–13 bony shields along the back and 29–31 along the side of the body. The European or Atlantic sturgeon is now mostly gone from overfishing. All the species are confined to fresh water. One of them is rare in the Mississippi and other rivers of North America, the other three occur in the larger rivers of eastern Asia; the beluga sturgeons of genus Huso, and the false shovel-headed sturgeons, of Scaphirhynchus’ sister genus, Pseudoscaphirhyncus, and are confined to Northeastern Asia. Contents by Wikipedia