strict sense of the term and that this herring ceases to eat for only a brief period immediately be- 

 fore and during spawning. 



Kun (6) considers that the herring behave in different ways at different biological stages. 

 This author examines the seasonal variations in the feeding rate and comes to the conclusion that 

 the Pacific herring does not feed uniformly throughout the year. 



Material and Methods 



For our study of the contents of the stomachs of herrings, we used adult specimens (caugjit 

 by drift-nets on the fishing grounds) 30-33 cm. long, since the bulk of the catches during the period 

 1951-4 consisted of large herrings. Most of the stomachs were collected during the summer. 



In 1955, owing to the large additions to the stocks of usable herring from the 1950 year class, 

 when the material was analysed it was divided into two size groups: herring 30-33 cm. in length-- 

 the older age group, and herrings 26-29 cm. --the 1950 year class. 



Upon comparing the stomach contents of the younger herrings (1950 year class) which had 

 spawned once with those of the older herrings which had spawned more than once, we were unable 

 to detect any difference whatever in the choice of food organisms in the same areas during the 

 summer. 



The material collected during the individual years is distributed as follows: 



Year Herring stomachs collected 



1951 640 



1952 280 



1953 397 



1954 395 



1955 1,600 



Total 3, 312 



For the feeding pattern of the herring, we used the method of quantity -weight analysis pro- 

 posed by V. G. Bogorov (2) and adopted by the Herring Laboratory of PINRO. We were unable to 

 analyse the feeding of the herring by the quantity -weight method in February, March, and April, 

 since, owing to circumstances beyond our control, the material was collected selectively, no re- 

 cord being kept of empty stomachs. We utilized this material not only for determining the qualita- 

 tive feeding pattern of the herring but also for ascertaining the characteristics of the herring's 

 capacity to feed actively during the pre -spawning period when food organisms are present. 



The specific composition of the food was determined only from the stomach contents (those 



of the intestines were not taken into account). 



The food mass, after being transfered to filter paper, was sli^tly dried, weigjied, and ex- 

 amined under a binocular microscope . 



The percentages of the individual components in the food mass were determined visually and 

 then recorded as percentages by weight. The amorphous mass present in the stomach was distri- 

 buted in projxirtion to the weight of those parts of the food mass which were being determined. 



For the curve of the feeding rate of the herring and of the size of the separate food compo- 



141 



