ROGERS: JUVENILE SOCKEYE SALMON 



Table 6. — Calculated mean lengths (live equivalent in mm) for 20 June and 20 July from weighted exponential 



regressions, 1962 through 1972. 



'Means calculated from lengths on 24 July 1963 and growth rate in 1968. 

 -1963 excluded. 



spawning occurs primarily in June and July, 

 and the entire lifespan is spent in Lake Alek- 

 nagik. 



Sculpin were the most uniformly distributed 

 of the fish commonly caught by beach seine, 

 but they tended to be more abundant at stations 

 where sockeye salmon spawning occurred 

 (Stations 2N, 5S, 6N, and 7S) than at other 

 stations. Roger (1971) discusses the role of 

 sculpins as predators on sockeye salmon eggs 

 in Lake Iliamna of the Kvichak River system. 



Arctic Char Fry 



Arctic char spawn in late fall. They are pre- 

 sumably in the lake by early June, although 



little is known of their reproduction and early 

 life history in Lake Aleknagik. In early summer 

 they are in the fry stage and range in length 

 from 25 to 50 mm. The adults are major preda- 

 tors of juvenile sockeye salmon and threespine 

 .stickleback (Nelson. 1966). 



Char fry averaged about 1 mm shorter than 

 sockeye salmon fry on 20 June and about 4 mm 

 shorter on 20 July. They did not differ signifi- 

 cantly in average length among the lake areas 

 on 20 June, but were smaller in area A than 

 in the other areas on 20 July (Table 6). 



Arctic char fry were the most unevenly dis- 

 tributed of the fish caught by beach seine and 

 occurred infrequently in catches. They were 

 more abundant in the upper I'egion of the lake 



1069 



