98 Puget Sound Marine Sta. Pub. Vol. 1, No. 11 



Results After Feeding Began 



Food was first given to the fisii on February 1. It consisted of boiled 

 pig's liver ground up very finely, to which for a couple of weeks, was 

 added hard boiled hens' eggs. The fish showed a marked preference for 

 the egg and ate it greedily. The fish were fed but once a day and that 

 not at the same hour of the day. Sometimes the feeding was done in 

 the morning, sometimes at noon and sometimes in the evening. The fish 

 Avould in all probability have done much better if they had been fed 

 regularly twice a day. But since both lots of fish were treated in exactly 

 the same way the results of this experiment would not be affected by 

 irregularity in feeding. 



It was impossible to determine whether the fish received the same 

 amount of food per capita as a considerable amount was swept away by 

 the water. In order to be assured that the fish had similar treatment, 

 more food was given them each time than they ate, so that at the next 

 feeding time there remained in the troughs a considerable amount of food 

 from the previous feeding. This refuse was as a rule removed before 

 fresh food was again given to them. From this time until July 1 the 

 black trough was covered with a board, a narrow crack being left along 

 the side of the trough away from the light. This was done in order that 

 the fish might have enough light to enable them to see their food. 



Another determination of relative weights was not made until March 

 13. On this date 15 fish were taken from the dark trough with one sweep 

 of the strainer, and in a similar way 36 were taken from the light trough. 

 Table 6 gives the results of this determination. By reducing the relation 



of the average weights to a percentage it is shown that the fish from the 

 dark weighed 15.2 per cent more than those from the light. 



The next determination of relative weights was made March 24. The 

 method of taking and drying the fish was the same as that previously 

 used. In table 7 the results are recorded. In this case the fish from the 

 dark trough weighed 16.33 per cent more than those from the light. 



Table 7. A comparison of the weights of fish taken Mar. 24 



