Region A (Areas 1-7) - Okhotsk Sea 

 off tbe vest coast of Kamchatka 



Region B (Areas 8-I3) - North Pacific 

 Ocean off the east coast of Kam- 

 chatka between U9' 30' N and 

 53' 30' N. 



Region C (Areas 11+-20) - North Pacific 

 Ocean frtan 165" 00' E. to 175" 00' 

 E. , and k8' 00' N. to 50" 00' N. 



Fish were frozen after capture, and 

 stored for periods varying from one month 

 to a year. They were then thawed, and 

 morpheme trie measurements were made, sex 

 and degree of maturity were detenained, 

 and the digestive tracts anterior to the 

 initial insertion of the pyloric caecae 

 were removed. The digestive tracts were 

 preserved in 95 percent ethyl alcohol and 

 stored in 8-ounce screw cap Jars. For chum 

 salmon only those stomachs which were con- 

 sidered to contain food items were made 

 available for study. For pink and sockeye 

 salmon, all stomachs regardless of content 

 were made available. These data are sum- 

 marized in table 2. 



The volume of the stomach content was 

 detennined by visual comparison with a vial 

 which had been graduated in milliliters. 

 For some larger items volume was detenained 

 by displacement in water. The displacement 

 volumes were multiplied by a factor of 5 

 (Redfield, 19'^l) and added to the settled 

 volimie. All results are reported as settled 

 volume in milliliters. 



Because a detailed analysis of the 

 food items in each stomach could not be 

 undertaken, items were listed as follows: 

 copepods, euphausiids, amphipods, pteropods, 

 fish, squid, and crustacean larvae. An 

 estimate of the percentage composition of 

 these forms in each stcmach was made by 

 examining the total contents, or an eiliquot 

 sample was taken and compared visually with 

 the remainder of tbe stomach contents to 

 detect any obvious sampling error. The 

 estimated percentage composition was an 

 approximation; however, the distinct dif- 

 ferences of feeding behavior between species 

 minimized errors from the rapid method of 

 study employed. 



Results 



Tabl« 2. — H^oiber of aalmoa stanacha studied 



Each species is treated separately 

 according to region of capture. The three 

 species sltc then compared to evaluate the 

 differences in feeding behavior. Table 3 

 gives for the stomachs having identifiable 

 remains the average volume, and the maximum 

 volume for a single stcmach for the three 

 species by regions. Tables k, ^, and 6 

 give in percent the frequency of occurrence 

 and the volume of the different food items 

 in the stomach contents of the three species. 



Stcmach contents were removed in most 

 cases on the same day that the stcmach was 

 obtained from tbe fish. However, seme 

 stcmachs were not processed for periods up 

 to two weeks. No difference in the state 

 of preservation of the contents of these 

 stcmachs could be discerned. 



Tbe contents of most of the stomachs 

 were preserved in screw cap vials varying 

 in capacity from 28 to h2 milliliters. The 

 contents of stomachs which contained leirge 

 items, such as fish and squids, were pre- 

 served in 8-ounce screw cap jars. The 

 preservative used was 95 percent ethyl 

 alcohol . 



Table 3. — Voluaes of stcaaclies haTlng 

 Identifiable reaalns 



