In marked carp of /iOO grams vreicht, I recorded a loss of weisht of from 10 to H per 

 cent, after a hibernation period of 16 days, in a pond, aveia^ing a temperature of from l^ 

 to 6 degrees centigrade. Their loss in length ranged from 3.3 to 6.7 per cent. 



B runner and Endress recorded in tench of 185 and 193 grams weight, a loss of from 7.7 

 to 7.8 per cent, at a water temperature of 7.5 degrees centigrade, starting the experiment 

 on November 7th and lasting 120 days. 



Demo 11 states that hungry carp may lose up to 35 per cent of their weight and tench 

 up to 50 per cent. During the first few days of malnutrition, nitrogen-free reserve 

 materials will be called upon, in an ever increasing rate, to provide the necessary 

 calories . 



Linda tedt records the loss in protein in a group of stajrving tench — for calorie needs — 

 as 51.^ per cent during the first day of a hunger period. It dropped to ^0.7 per cent on 

 the forty-third day, vhen it again rapidly increased to 62.5 per cent on the sixty-third 

 day. 



It follov;s that the far more important proteins will be used up for caloric needs, 

 once the reserve materials have been exhausted. 



3 runner and Endress observed that fat, above all, will be used up during hunger periods, 

 and that other parts of body structure — rich in protein — will eventually also suffer, muscles 

 and intestines, for instances. 



I have made an experiment in order to ascertain the influence of previous undernourish- 

 ment upon growth, after resuming proper feeding. The experi.ient was made v;ith normal A years 

 old carp of about the size of 2 years old, and v;ith fish of the same parentage and same size 

 but greatly undernourished. Table I gives the respective figures. 



Table 1. 



Length and weight of individual fish 

 (in centimeters & in grams) 



Individual increase, average 

 from: 



at time of stocking 



at time of fishing 



quoted 

 figures 



whole stock 



Under- 

 nourished 



Normal 



30 cm 392 g) 

 29.5 " 339 g) 

 28 " 292 g) 



30 

 29 

 29 



" U3 g) 

 " A2A g) 

 " ^OA g) 



aver. 

 342 g 



aver. 

 425 g 



43 



41.5 



40 



43 

 42 

 40 



cm 1355 g) 

 " 3235 g) 

 " 1240 g) 



" 156a g) 

 " 1660 g) 

 " 1580 g) 



aver. 

 1280 g 



aver. 

 1600 g 



938 g 



1175 g 



1023 g 



1212 g 



Losses were alike in both categories. Although the "lean" carp were no longer under- 

 nourished, when fished out, the proportions in weight to size had remained constant in 

 con^jarison rith the "normal" carp. The "lean" fish had remained "slimmer". On the other 

 hand, their capacity to recuperate from previous loss of weight v;as hardly impaired, not- 

 withstanding their state of great emaciation. 



Size as well as state of nutrition depend therefore upon numerous "external" and 

 "internal" conditions. 



As essential "external" conditions, we have to regard v.cter tejip^rature and food supply. 



The most ir5»ortant "internal" factors are the inherited faculties for rapid growth, 

 good food-conversion and for resistance. Grov.th and highest possible v/eight attainable with- 

 in the different categories of fish (with advancing age) depend upon these factors. 



