Table 13. 



Tleight and number of eggs of brown trout 

 of different sizes, but of same age. 



The weight for an egg represents the average weight, as calculated from all of 

 them, and from one and the same female. Aside from these test fishes, numerous others 

 were also investigated. Isolated cases of exceptions always occurred. 



Similar regularities, based upon practical experiences with rainbow trout were 

 found by Quirll . In table Li, I record his findings. 



Table U. 



Number of eggs from rainbow trout 

 of different sizes and ages. 



Tfeight and age of the 

 individual female. 



Number of eggs 



CaQ.culated number of 

 egt;s per kilogram. 



1650'gr. 5-6 years 

 875 " 3-«4 " 

 750 " 3-A " 



2900 

 2ii00 

 1900 



1750 

 2750 

 25^0 



tiiast also has demonstrated that the number of eggs per kilogram drops when the 

 weight of fish rises over 200 to 250 grams. Ihfortunately, he did not properly segre- 

 gate age and weight in calculating his findings. 



But from all this we derive the practically in^Dortant knowledge that e^:gs from 

 larger and older fish (i.e. larger eggs in general^ cause substantially greater outlay 

 than eg^s from younf^ and smaller broodstock . 



The size of eggs is important for the fishbreeder since larger eggs produce a larger 

 fry than smaller ones. Sklower confirmed this law through experiments with brown trout 

 and also demonstrated that the size of parent males, used in stripping has no influence 

 iihatever upon the size of the procenjr. Frj'' from small eggs remained smaller all through 

 the first year than fry from larger eggs. In this respect is must be remembered, though, 

 that the size of the father fish depend upon hereditary good food assimilation. Their 

 progeny can therefore only be judged after they begin to feed and after eventual unfavor- 

 able paratypical influences (size of eggs) have disappeared, I have had the same 

 experiences as Sklower with rainbov; trout. In this case, the mortality among finger- 

 lings from ver:/ small eggs was very high during the first summer. 



Table 15 shows conclusively that the size of eg^s* (and consequently of alevins) is 

 functionally depending upon the size of the mother fish and not upon their age. The 



* Lleasureraent of eggs by ocular micrometer, "egg pincettes" are unusable. 



103 



