162 REPOET OF COMMISSIONEE OF FISH AND FISHERIES. 



above it is to be met with nowhere else in Europe. It also occurs in the 

 Black Sea, but .only near its shores, and also in the Dnieper, which dis- 

 charges its water into the Black Sea near Odessa 5 likewise in the Volga 

 and Ural Elvers of the Caspian Sea. 



The Danube salmon has not the peculiar habit of migration from 

 the seaof the true salmon [Salmo salar) though it also ascends the rivers to 

 spawn, like most other tialmonida\ Differing from the other European 

 salmon, however, which breed in autumn or winter, it deposits its eggs in 

 March, April, and May, the female making large cavities in the middle 

 of the river for the purpose, called by the fishermen of the Dan ube ' bruch,^ 

 (break.) Accompanied by several males the female fish deposits its eggs 

 at the bottom of these excavations, and while thus engaged are easily 

 caught with the ' trident,' or fish -spear, and even after one of the males 

 has been takenont the othersleave theplaceonlyforashort while to return 

 and meet the same fate. Many fish are thus cai)tiired during the breeding 

 season, greatly to the injury of the fisheries ; and although laws prohibit- 

 ing this mode of fishing during the breeding season have beeu enacted 

 in all the littoial states of the Danube they are mostly evaded. 



The eggs of the Danube salmon have a diameter of about .20 of an inch, 

 and their yolk is not a connected mass, as in the eggs of the other Sal- 

 monida;, but is distributed in oily drops upon the entire inner surface. 

 A period of forty to fifty days in cold weather, even more, is necessary 

 for hatching. The eggs are rather sensitive and suffer greatly from the 

 rapacity of the grayling, ThyrimUus ve.riUifer Agassiz, which exist in 

 great luimbers in the tributaries of the Danube. They follow the female 

 liucho in shoals, and voraciously consume the eggs. Hence this beauti- 

 ful fish is never so abundant us is the /Sdhno saJar in the Rhine, where the 

 TldjmaUus is far less numerous than in the Danube. In addition to this, 

 the season for deposituig their eggs is far more favorable to the 8. salar, 

 since then the ThijmaUus are full of milt and eggs and less hungry than 

 at spring-time, when they have just done spawning. The young fishes 

 lose their yolk-bag after ten to eighteen days. Th<^y have a length of .SO 

 of an inch when hatched, to G.30 inches when six months old, and 

 24 to 32 inches after two years. This rate of growth is quite favorable, 

 when compared with that of the European brook-trout, but is less than 

 with the other SaJmonidw, which, migrating to the sea, there find richer 

 nourishment than the hucho,v:hich generally remains in the river; Since 

 the hucho does not enter the sea, for this reason it appears especially 

 adapted to the large lakes of America, as well as to the Mississippi and 

 its tributaries. . 



In its third year the Salmo hucho attains its maturity for propagation. 

 Before that period it prefers to remain in the small rivulets; but Avhen 

 sufficiently grown prefers the most rapid places of the larger tributaries, 

 where rocks, trunks of trees, &c., otter shelter. Like the 8. salar, it 

 ascends obstructions several feet in height, sometimes six to eight. 

 Like the other large SalmonidcE it is a rapacious fish, neither more nor 



