REPORT OF COMMISSI 0:NrER "OF FISH AND FISHERIES XXXIX 



in, and derive tbeir chief growth from, the sea. At certain seasons of 

 the year, when fat and plump, they entt^r the rivers and proceed usually 

 as far as the obstructions will permit, or until they find their proper 

 spawning-ground; here the eggs are discharged, fertilized, and hatched. 

 The adults either return immediately to the ocean or after a certain 

 interval. The young fish spend a certain period in the fresh waters, 

 feeding, it is true, but on minute organisms, which are always procurable 

 in abundance. 



Shad and herring enter the rivers and spawn in the spring, and the 

 young return in the autumn. The eastern salmon enter the rivers in 

 spring, and spawn in the autumn, the eggs not hatching until late in 

 the winter. The young remain for one and some of them even for two 

 years, and then go down to the sea. After a certain interval these fish 

 return to their birth-place, the shad, at the age of three or four years, 

 weighing from three to five pounds ; the salmon after the same interval, 

 weighing from nine to twelve pounds ; this immensely rapid growth 

 having taken place in the ocean, and without requiring anything in 

 the way of human intervention. For this reason it is that the efforts 

 necessary to the multiplication of anadromous fish may delimited to secur- 

 ing a proper passage of the adults to and from their proper spawning- 

 grounds, or, in addition, to the securing of their eggs in numbers, and 

 placing the young when hatched, and after a suitable interval, in the 

 water where they are to pass the period of their infancy. Nothing, 

 therefore, is asked of the waters but the right of way, the adults rarely 

 taking food of any kind while in the rivers. Their sustenance during 

 this period is derived from the surplus of fat in their own bodies, and 

 the exhaustion jiroduced by this period of abstinence, especially with 

 its accompaniment of the development of the eggs and their fertiliza- 

 tion, being made up by the voracity of their feeding on returning to 

 the ocean. 



The species just mentioned all live in the ocean and run up into fresh 

 water to spawn ; the list being capable of considerable addition. Other 

 fishes, again, live in large bodies of fresh water, as lakes, and run into 

 tributary streams or outlets for a similar purpose, and are thus anadro- 

 mous likewise. The Coregonus or white-fish, are almost universally ana- 

 dromous ; also the land-locked salmon, the oquassa-trout, or blue-back, 

 the fresh- water smelt, &c. 



In this connection it may be interesting to refer for a moment to the 

 difference in habits between the common eel and the species just 

 referred to. This, like the others, is an anadromous fish, or better, 

 perhaps, catadromous, the order of its movements being reversed. The 

 eggs of eels, for the most part, are laid in the sea, and the young, after 

 a short interval, enter the mouths of rivers and streams in early summer 

 and pass up as far as an open passage will permit. The adventurous visi- 

 tor to the Cave of the Winds, under the water-sheet of Niagara Falls, is 

 struck as much by the immense number of young eels swarming against 



