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Fishery Bulletin 97(4), 1999 



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groups. The most important food of the smallest 

 (<25 cm) size group of Atka mackerel were calanoid 

 copepods ( 35^f by weight ) and larvaceans ( SS'/r ). The 

 most important prey of Atka mackerel between 26 

 and 35 cm FL were calanoid copepods (35%) and eu- 

 phausiids (29% ). The largest size group (>35 cm) of 

 Atka mackerel consumed a substantial amount of 

 calanoid copepods ( 18% ), in addition to euphausiids 

 (22%). Miscellaneous fish (walleye pollock, cottids, 

 myctophids, and zoarcids) represented approximately 

 9% of the total weight of stomach contents of the larg- 

 est size group of Atka mackerel. Atka mackerel eggs 

 (as evidence of cannibalism) were found almost ex- 

 clusively in the largest size group, representing 11% 

 of total weight of stomach contents. 



Walleye pollock were the most common fish spe- 

 cies in the Atka mackerel diet. The size of walleye 

 pollock consumed ranged from 49 to 63 mm SL with 

 a mean and SD of 56.2 mm and ±4.8 mm, respec- 

 tively. The cottids consumed by Atka mackerel ranged 

 from 12 to 21 mm SL with mean and SD of 15.9 mm 

 and ±3.1 mm, respectively. In addition, Atka mack- 

 erel stomach samples contained one bathylagid 



