VALUE OF NORWEGIAN LAKES FOR FISH CULTURE. 551 



the natural culture becomes superfluous for the fish species concerned, 

 which ought to be the object of cultivation, and absolutely injurious in 

 so for as one, from his anxiety to advance this culture, seeks to eradi- 

 cate or omit to stock the water with other kinds of fishes which might 

 serve the cultivated fishes as food, even if they in any degree concur 

 with this about other means of food, for the fishes which one cultivates 

 will chiefly be fish of prej^, which will develope with a desired rapidity 

 only when they have an abundance of other fishes as food. 



The essential condition for abundant production of fish, next to the 

 possession of water, is ability to be able to get fish-spawn in the de- 

 sired quantity. This ability will always be present in all well-stocked 

 fishing waters if no injurious law regulation places an artificial barrier 

 by prohibiting the cai)ture of spawning fish at the right season, that 

 is, at the spawning time itself. Every trout or salmon yields 2,000 eggs 

 per kilogram (two pounds) of its weight. To procure 1,000,000 eggs there 

 will thus be required fish of the united weight of about 500 kilograms, 

 but few males being required in i)roportion to the females. After the 

 lapse of a year, one will have at least 800,000 young fishes of one-twen- 

 tieth to one-tenth of a kilogram each, or 60,000 kilograms in place of 

 500 kilograms. If, therefore, the mothers and fathers which are taken 

 as spawning fish must be consumed and a portion more are taken under 

 the same pretext, this signifies nothing in the face of the certainty of 

 having brought back the necessary young which, even as yearlings, will 

 weigh fully one hundred times as much. 



It was just to prevent the loss of profit in fishing at the close-season 

 that the existing legal enactment for salmon was made. This misun- 

 derstanding of real interest, this injurious prohibition will probably dis- 

 appear when the pending new proposition for a change in the fish law 

 obtains legal validity. Besides, the spawning-fish are alwaj^s poor food 

 in comparison with what they are at other times of the year. In Eng- 

 land such spawning fish are considered inedible, and* such will also be 

 the case in tbis country when a greater abundance of fish no longer 



the eggs with, gravel by sweeping over them with her tail all that is fountl near the 

 nest. If the female is not satisfied with the covering she will go into the stream and 

 push suitable stones backward with her ventral fins over the nest until it is completely 

 covered. After a few minutes the male returns to see how the work ^irogresses, eats 

 some eggs if he can find any, and departs again. The female, on the contrary, dees 

 not go away, but remains at the place and does not forsake it until all the eggs are 

 spawned, which occurs in many installments and occupies a long time, often as much 

 as three days. The female, as well as the male and all the hangers-on swimming 

 around, have meanwhile eaten as many as they -could of the eggs. When the first pair 

 has left the place another comes on the same errand. The female finds a suitable 

 place and begins to jirepare a nest. As soon as the first-spawned eggs apxjear this bus- 

 iness is given up and female and male vie with the lookers-on in eating all the roe be- 

 fore they again resume work. If one nest takes into account that all kinds of water 

 fowl seek after the spawn with great eagerness, that the tender young fish coming to 

 life in the spring servo in great portion as food for the larger fishes, it is no wonder 

 that there are so few trout in our streams, but a great wonder that any are left." — 

 (Trout-culture, by Seth Green. 1870.) 



