474 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Table 8. — Comparison of stomach contents of equatorial albacore (A) and yeUowfin (YF) tuna taken on longline 

 more than 25 miles from land during cruise 11 of the John R. Manning 



 Unidentified. 



5. The food of albacore was found to consist 

 mainly of a variety of fisli, squid, and crustaceans, 

 the percent by volume of each differing according 

 to the method of capture, as shown by the follow- 

 ing. Longline : fish, 47 percent; squid, 41 percent ; 

 crustaceans, 6 percent. Gill net : fish, 34 percent ; 

 squid, 62 percent ; crustaceans, 2 percent. Troll : 

 fish, 79 percent; squid, 11 percent; crustaceans, 6 

 percent. Representatives of 32 fisli families and 

 11 invertebrate orders were found in the food of 

 longlined albacore, compared to 9 fish families and 

 10 invertebrate orders for troll-cauglit albacore, 

 and 4 fish families and 5 invertebrate orders for 

 gill net-caught albacore. 



6. Fishes of the families Gempylidae and 

 Bi-amidae dominated in tlie fish portion of the diet 

 of albacore from the equatorial Pacific, wliile 



sauries ( Scomberesocidae, Cololabls sp.) domi- 

 nated ill albacore caught in the temperate North 

 Pacific. KSquid were well represented in the alba- 

 core captured by all three methods. The main 

 difference in crustaceans was the lack of stoma- 

 topods (Squillidae) in the diet of troll- and gill 

 net-caught albacore. 



7. Tlie liigher average stomach content of long- 

 line-caught albacore (26.7 cc.) was attributed to 

 the larger sizes of these fish. Tlie differences in 

 the average stomacli content of approximately the 

 same size gill netted (9.8 cc.) and troll-caught al- 

 bacore (15.1 cc.) were attributed to differences in 

 the method of capture. Gill netted albacore are 

 taken at night, when feeding is probably at a re- 

 duced rate, since 80 percent of the gill netted 

 albacore had stomach contents less tlian 1 cc. 



