THE FISHERY INTERESTS OF AUSTRIA. 617 



roe, packed in kegs, comes into the trade as caviar, and the inner skin 

 of the air-bladder is made into isinglass. 



Most fish of the sturgeon family are found in the Black Sea, the Sea 

 of Azov, and the rivers flowing into them ; some of them are found in the 

 Danube beyond Pressburg. 



All attempts to hatch sturgeon -eggs and to raise the young artificially 

 have so far been failures; and, only recently, Dr. Koch, in St. Peters- 

 burg, is said to have succeeded in solving this problem. 



The common sturgeon (Acipenser sturio) is found in the Atlantic 

 Ocean, the Mediterranean, the Adriatic Sea, the North Sea, and Baltic, 

 and ascends very far up the rivers. 



The huso (Acipenser huso) weighs as high as 2,500 pounds, and ascends 

 the Danube and some of its tributaries. On account of the persecutions 

 to which it has been exposed on the Lower Danube, it has at present 

 become very rare in Austria. 



The finest kind of sturgeon, whose flesh is almost as high-priced as 

 that of the salmon, is the sterlet, (Acipenser ruthenus,) which seldom 

 measures more than two feet, and weighs from 8 \ to about 9 pounds. 

 It stays longer in the rivers than the other sturgeons, requires spawning 

 places with gravelly bottoms and considerable fall, and is found in the 

 Danube as far as Bavaria, in the Salzach, the Drau, and other tribu- 

 taries, as well as in the Dniester, &c. Its air-bladder makes the finest 

 isinglass. 



The sterlet has recently been cultivated to a considerable extent in 

 North Germany at the suggestion of the Deutsche Fischerei-verein. The 

 Prussian ministry of agriculture, in 1872, accepted an offer of Dr. Koch, 

 in St. Petersburg, to bring 100,000 young sterlets from the Yolga 

 to Germany, where they are to be distributed among the public rivers, 

 private waters, and especially to piscicultural establishments. 



20.— THE CRAWFISH, (ASTACUS FLTJVIATILIS.) 



The river crawfish (Astacus fluviatilis)* is considered to be very different 

 from fish in the systems of naturalists ; but, in the practical fisheries, it 

 has to be treated in common with them, and the same legislation should 

 apply to both. It is found in nearly all of our rivers, brooks, and even in 

 ponds, though not always in such quantities as to supply cheap food for 

 the masses of the people. With proper care, their numbers could easily 

 be increased; all that has to be done is to give them cheap food, to 

 observe the times when they should not be caught, and to plant alders 

 and other bushes on the banks of those streams which, by too extensive 

 fishing, have become drained of crawfish. 



In France, the government has granted an appropriation by which 

 more than 300 rivers and brooks can be stocked with German crawfish. 

 Even these are not sufficient to supply the great demand, and large num- 



*One species of Astacus is considered a great table delicacy in Europe and sells at 

 high prices. — S. F. B. 



