Ttible 19. 



Directions for the stocking of carp ponds, trout ponda and of holding ponds, 

 based upon average production, normal stock weight and normal stock increase. 



Abbreviations - B: brook trout; C: carp; Rt rainbow trout; Tj tench. 

 Bo, Ro, Cq, Tqi fish with vitelline sac. 

 Bi , R^, Ci, Tj^x yearlings of respective species. 

 Plgures 2 to 6 below letters B, R, C, T mean 2 to 6 years. 



C Kind of ponds or tanks Number, kind and age of fish to be set out. 



C spawning pond 2 females, A moles 



C nursing pond 50,000 broodlings per hectar (2^ acres) 



C rearing pond 5,000 fingerlings " " 



C holding pond (non-fed) 500 yearlings " " 



C n " (fed) il,500 « ■ « or mixed stocki 



(1,000 Ci plus 2800 Tl per hectar. 



C adult ponds, non-fed 100 C2 per hectar 



C » » fed p50 C2 " " or mixed stocki 



(200 C2 plus 200 TJ per hectar. 



C winter ponds 1 Co per square meter 



C fish tank 100 C3 " " ■ (I50 kllogrsM per 



cu. meter) 



C earth ponds 10 - 20 C3 • " 



T rearing ponds 2,500 yearlings per hectar 



T holding pcxid (non-fed) 65O T2 



T » " (fed) 2,000 T2 



C holding Pond) q^. 



T spawning ■* ) 1 T3 female plus 2 T3 males per hectar 



(Incubation pond) 2BoorRo per square centimeter. 



(Brood pond (natural) .... 2 6oorRo'* " meter. 



( ■ " (feeding) .... 100 Bo or Rq " " ■ . 



Troutt (Fattening ponds 



(intensive feeding) 25 Bi or Ri_ " " " . 



(Spawning ponds) 1 to 10 B/ to B/ or R, to R^ per are 



^ (l/lOO hecter) 



Chapter VII 

 nSH FEEDING 



A. Importance of feeding . 

 The food quotient as standard of good results . 



The profits to be derived from pond fishei*ies are greatly increased through the 

 feeding of fish. In trout ponds, the fish — through feeding — becoae independent of the 

 natural catabolic cycle of the pond. In carp fisheries, additional feeding allows 

 greater stock density and stimulates the fish to a better utilization of the natural 

 food. Under the climatic conditions of Germany, it would filmost be impossible to pro- 

 duce carp for the market, upon a profitable basis without the aid of feeding. 



Qualitative differences of the food, in relation to the differences in age are 

 seldom made, since there is no difference in fish between a period of mere growth and 

 periods of fattening them; like in the case of cattle. 



In carp culture, where natural food is such an important factor, only the form of 

 food is adjusted to the size of fish. All other adjustments are superfluous, often even 

 with regard to proportional issuance of rations. 



The composition and theoretical physiological values of artificial foodstuffs has 

 been dealt ndth in table /», but aside from some especial factors, it is not so much the 

 physiological food value as the price of food wfaidi is of interest to the fishbreeder. 

 Fish food must be cheap. 



131 



