the sensitive yearling carps from the autumn disease favoring ilshS-ng -out and the wintering 

 over in small food-poor hibernating ponds. In this procedure, contrary to other growing 

 methods, the autumn fish-out may be omitted because the rearing ponds are already stocked 

 with relatively large little fishes among which losses can hardly occur. The atodcing of 

 the rearing ponds can therefore be so planned that in the following spring there will be 

 yearling carps of fairly accurate predetermined size and numbers on hand. The calculated 

 result can also be controlled by repeated weir catches. Surprises are not to be feared 

 in the nursing procedure. 



According to prevailing conditions, such as productivity, fertilizing, adopted bottom 

 culture, feeding, etc., the storing of rearing ponds vacLes, of course. In average, one 

 figures about 5,000 carp per hectar (2 1/2 acres). Proper storage capacity will soon be 

 learned from eventual mistakes made upon this point. 



If large yearlings of over 14 centimeters length are desired, the storage should 

 not surpass 1,000 to 1,500 carps per hectar. If yearlings londer 10 centimeters length 

 are wanted, the ponds can be stored with 10,000 carp per ha., and under favorable con- 

 ditions with even twice and three times that number. The losses, generally incurred, 

 from the eighth day to the yearling carp, do not amount to more than 10 to 15 percent in 

 good ponds but can be greater at times. 



Yearlings — ^when sorting them out — are generally graded in three classes, to wit: 

 carp from 6 to 9 centimeters long, from 9 to 12 centimeters and from 12 to 15 oentlneters 



(see Fig. 2), 



It is my personal opinion that yearlings of less than 10 centimeters length are 

 inferior in every respect and especially are lacking in resistance to hibernation and to 

 disease germs (the latter attack the brood just at that tijne). On the other hand, the 

 raising of all too large yearlings has also its disadvantages. Such fish need far too 

 much food for more sustenance in proportion to the food necessary for growth and are 

 therefore an altogether unprofitable stock. 



Yearlings bring usually 50 percent higher prices per weight unit than 2-year-old 



carps. 



The nursing ponds, after fishing them out (usually in April) are drained and left 

 to dry until a few days before restocking them. Nursing ponds as well as rearing ponds 

 are thoroughly worked over, fertilized, sown with grass, etc., so as to reach and maintain 

 first class productivity independent fi-om regional condition. 



The raising of carp fingerlings and of yearlings 

 in spawning and rearing ponds. 



This method according to Schaeperclaus (1930) is used by almost half of all pond 

 fisheries in Northern Germany and is really nothing else but the Dubisch method minus 

 the use of nursing ponds. It is claimed that this method has a particular advantatge, 

 to wit: The broodlings are transferred directly from the spawning ponds into the larger 

 and relatively less crowded ponds, whereby the fish are less exposed to contagion from, 

 parasites and from disease germs. The fishing-out during summer is thereby avoided. 



In reality, it was perhaps mostly scarcity of water and lack of expeidence, some- 

 times perhaps more negligence, which led to the introduction of this method. The 

 elimination of nursing ponds makes the work easier for the fishbreeder, but it will in- 

 variably lead to more primitive conditions, in short one takes his chances with this 

 method. 



Rearing ponds will have to be fished out in the autumn since the actiial production 

 cannot be known otherwise. The actual production cannot otherwise be summarized, except 

 that very thorough experiences have been accunailated by means of repeated yearly weir 

 catches, so that the yield may be reliably estimated in advance. Since the losses 



86 



