SUMMARY 



1. A difference in size between the sexes is exhibited by bigeye tuna 

 in samples from the western Pacific and the Hawaiian Islands. 

 The modes of the male size distributions are about 14 cm. or 30 

 pounds larger than those in female size distributions, 



2. Dominant modal groups do not occur in the Hawaiian commercial 

 catch every year, but rather exhibit a cycle that appears to have a 

 period of about 2 years, apparently the complement of the cycle in 

 the Japanese North Pacific fishery. 



3. Homologous modes that appear during alternate years in the Ha- 

 waiian fishery are not identical in size; rather they increase 

 slightly in size with each recurrence. 



4. Approximately similar growth rates and the presence of approxi- 

 mately 2-year cycles of dominant size groups in the catches of 

 both the Hawaiian fishery and the Japanese North Pacific fishery 

 suggest there is a relationship between the bigeye tuna of the two 

 areas. 



5. A plot of bigeye weight frequencies by months from the Honolulu 

 market for the period November 1947 through December 1954 re- 

 veals modes that progress consistently from smaller to larger 

 sizes. 



6. A provisional growth curve plotted by connecting modes found in 

 these size distributions indicates that Hawaiian bigeye nnay gain as 

 much as 50 pounds in 1 year and may live about 6 or 7 years. 



7. In the vicinity of the Equator bigeye modes do not progress with 

 time. 



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