ABSTRACT 



This report presents the results of a study of gonadal development and spawn- 

 ing in the albaeore, Germo alalunga (Bonnaterre). The study is based on exam- 

 ination of the reproductive organs, principally the ovaries from albaeore collected 

 in three general areas: the North Pacific, the Hawaiian Islands, and the central 

 equatorial Pacific. 



The ovaries were classified in three stages of relative maturity: early develop- 

 ing, late developing, and advanced, on the basis of the most advanced eggs pres- 

 ent. According to this classification, the early developing category included the 

 thin ribbonlike ovaries from sexually immature fish as well as ovaries from the 

 larger, adult fish which showed no signs of egg development beyond this particular 

 stage. The other two categories, on the other hand, included only ovaries from 

 adult fish. 



The North Pacific albaeore were either juveniles or sexually dormant adults 

 with early developing gonads. The Hawaiian albaeore showed varying degrees 

 of maturity from early developing to advanced, with the bulk of the ovaries in 

 the late developing stage. The ovaries from central equatorial Pacific fish were 

 in the early developing and late developing stages, with the early developing stage 

 predominating. 



Our data show that albaeore taken north of Hawaii by research vessels of the 

 Pacific Oceanic Fishery Investigations, as well as albaeore taken by the Japanese 

 in the spring live-bait and winter longline fisheries, and those in the American 

 west coast summer fishery are nonspawning fish, either juveniles or adult fish 

 whose gonads show no signs of incipient or past spawning. Albaeore apparently 

 do not spawn in the temperate waters of the North Pacific. On the other hand, 

 it appears that the albaeore in the region of the Hawaiian Islands and in the 

 central equatorial Pacific represent a segment of the population which, after attain- 

 ing a certain size in temperate waters of the North Pacific, moves south into 

 tropical and subtropical waters to reproduce. 



