(Exocoetidae), which were not found in the 

 stomachs of the little tunny. In view of the lack 

 of specificity in the diets, it is probable that if 

 all four species were present in the same area 

 at the same time, they would vie with each other 

 for whatever food was available. 



Reliance upon inshore fauna was evident in 

 the stomach contents of all four species, but 

 this is not surprising since all of our catches 

 were made relatively close to land. The pelag- 

 ic larval and juvenile stages of many of the food 

 fishes were those of species which spend their 

 adult stages among the reefs or waters close to 

 the reefs. This holds true for some of the in- 

 vertebrates also. Undoubtedly the reefs of 

 Kaneohe Bay and adjacent areas play an impor- 

 tant role in contributing food to the area sampled. 

 However, the extent of this contribution is 

 presently unknown. 



SUMMARY 



Catch, catch rate, lure preference, size 

 frequencies, weight-length relations, sex 

 and maturity, and food are reported for 

 tunas and other pelagic fishes caught by 

 trolling off Kaneohe Bay, Oahu. Trolling 

 operations were conducted aboard the Uni- 

 versity of Hawaii's research vessel Salpa 

 during 1951 through 1955. 



Beyond 68 cm. male dolphin tended to be 

 heavier than females at a given length. 



6. The sex ratio of skipjack showed a prepon- 

 derance of males. Gonad examinations in- 

 dicate that skipjack may mature in 1 year. 

 The sex ratio of little tunny showed approx- 

 imately an equal proportion of males and 

 females. Gonad examinations showed the 

 majority of little tunny in the "maturing" 

 stages, with a few mature and spent fish. 

 The sex ratio for yellowfin was similar to 

 that of the little tunny. Gonad examinations 

 revealed no mature yellowfin. The sex 

 ratio of dolphin showed a preponderance of 

 females, although there was considerable 

 diversity in the sex ratio between schools. 

 Gonad examinations revealed the presence 

 of mature females but no mature males. 



7. Food analyses showed that the diet of these 

 pelagic fishes comprised primarily fishes, 

 cephalopods, and crustaceans. Some evi- 

 dence of interspecific competition for food 

 was indicated. Reliance upon inshore fauna 

 was evident in the stomach contents of all 

 the species examined. 



2. The bulk of the catch was composed of skip- 

 jack, dolphin, little tunny, and yellowfin. 

 The highest availability for all species 

 combined occurred in the months of May to 

 October. Yellowfin availability was consis- 

 tently high during September and October. 



LITERATURE CITED 



BERRY, S. S. 



1914. The cephalopoda of the Hawaiian 

 Islands. U. S. Bur. Fish., Bull. 32 

 (for 1912): 255-362. 



3. Among the various types of lures used, no 

 preference was found with respect to form 

 or color of the lure. 



4. Weight distribution of skipjack showed no 

 progression of modes, indicating migration 

 away from the fishing area as the fish grew 

 larger. The majority of the skipjack were 

 presumed to be "1-year-olds." Weight dis- 

 tribution of little tunny appeared to indicate 

 the presence of two and possibly three age 

 groups. Weight distribution of yellowfin 

 indicated growth from 5 or 6 pounds in June 

 to 10 pounds in November. Weight distribu- 

 tion of dolphinappeared to indicate bimodal- 

 ity in fish less than 10 pounds. 



5. Weight-length relations were calculated for 

 skipjack, little tunny, yellowfin, and dolphin. 



BROCK, V. E. 



1950. Keys to Hawaiian Fishes. Hawaii 

 (Terr.) Div. Fish and Game, Spec. 

 Bull. No. 4, 191 p. 



1954. Some aspects of the biology of the 

 aku, Katsuwonus pelamis, in the 

 Hawaiian Islands. Pacific Science 

 8(1): 94-104. 



EDMONDSON, C. H. 



1946. Reef and shore fauna of Hawaii. 

 Bernice P. Bishop Mus., Spec. Publ. 

 22, 381 p. 



HERALD, E. S. 



1949. Pipefishes and seahorses as food 

 for tuna. California Fish and Game 

 35(4): 329. 



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