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FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



8. The presence of egg remnants in the ovaries 

 indicated that most of the Hawaiian fish had 

 spawned previously. None of the ovaries from 

 the North Pacific contained egg remnants. Of 66 

 central equatorial Pacific ovaries, 20 contained 

 egg remnants. Remnants of eggs were present in 

 ovaries in all stages of maturity from early 

 developing through advanced. 



9. The minimum size at which albacore attain 

 sexual maturity and participate in spawning 

 appears to be about 90 cm. (weight, 33 lbs.). 



10. The size distribution of eggs within an 

 ovary, as well as the frequent occurrences of egg 

 remnants in advanced and late developing ovaries, 

 indicate that albacore may undergo at least two 

 spawnings during a spawning season. 



11. Assuming that all of the eggs comprising 

 the most advanced group within an ovary are 

 extruded in a single spawning, the number released 

 per spawning is about 1 to 2 million eggs per 

 individual female albacore. 



12. Ovary size is not a reliable criterion to 

 follow in assessing the degree of maturity of an 

 ovary. Relative ovary weight (ovary weight X 

 10 3 /virgule fish weight) is shown to be the more 

 reliable index, particularly for segregating early 

 developing from late developing ovaries. 



13. This study shows that albacore caught by 

 POFI vessels north of Hawaii, as well as those 

 taken by the Japanese spring live-bait and winter 

 longline fisheries, and those supporting the 

 American west coast summer fishery are non- 

 spawning fish that are either juveniles or adult 

 fish whose gonads give no signs of incipient or 

 past spawning. Albacore apparently do not 

 spawn in the temperate, waters of the North 

 Pacific. 



14. It appears possible that the albacore in 

 region of the Hawaiian Islands and in the central 

 equatorial Pacific represent a segment of the 

 population which, after attaining a certain size in 

 temperate waters of the North Pacific, moves 

 south into tropical and subtropical waters to 

 reproduce. 



LITERATURE CITED 



Blunt, C. E., Jr. 



1954. Two mid-Pacific recoveries of California-tagged 

 albacore. Calif. Fish and Game 40(3): 339. 



Brock, V. E. 



1943. Contribution to the biology of the albacore 

 (Germo alalunga) of the Oregon coast and 

 other parts of the North Pacific. Stanford 

 Ichthy. Bull. 2(6): 199-248. 



1954 Some aspects of the biology of the sku, Katsu- 

 womus pelamis, in the Hawaiian Islands. 

 Pacific Science 8(1): 94-104. 

 Clark, Frances N. 



1929. A racial comparison of California, Hawaiian 

 and Japanese albacore (Germo germo). Calif. 

 Fish and Game 15(4): 351-353. 



1934. Maturity of the California sardine (Sardina 

 eaerulea) determined by ova diameter meas- 

 urements. Calif. Dept. Fish and Game, Fish 

 Bull. 42: 49 p. 

 Ego, K., and T. Otsu. 



1952. Japanese tuna-mothership expeditions in the 



western equatorial Pacific Ocean (June 1950 

 to June 1951). Com. Fish. Rev. 14(6): 

 1-19, U. S. Fish and Wildlife Service. 

 Ganssle, D., and H. B. Clemens. 



1953. California-tagged albacore recovered off Japan. 



Calif. Fish and Game 39(4): 443. 

 Ishii, K., and M. Inoue. 



1956. Some notes on the ovary of albacore, Germo 

 germo, taken from the Coral Sea. Bull. Jap. 

 Soc. Sci. Fish. 22(2): 89-93. (Translation 

 from the Japanese by W. G. Van Campen in 

 the files of Pacific Oceanic Fishery Investiga- 

 tions Library.) 

 June, F. C. 



1950. Preliminary fisheries survey of the Hawaiian- 

 Line Islands area. Part I. The Hawaiian 

 long-line fishery. U. S. Fish and Wildlife 

 Service, Com. Fish. Rev. 12(1): 1-23. 



1953. Spawning of yellowfin tuna in Hawaiian waters. 



U. S. Fish and Wildlife Service, Fish. Bull. 



54(77): 47-64. 

 Kishinouye, K. 



1923. Contributions to the comparative study of the 



so-called scombroid fishes. Jour. Coll. 



Agric, Imp. Univ. Tokyo 8(3) : 294-475. 

 Otsu, T. 



1954. Analysis of the Hawaiian long-line fishery 



1948-52. U. S. Fish and Wildlife Service, 



Com. Fish. Rev. 16(9): 1-17. 

 Otsu, Tamio, and Richard Uchida. 



1959. Study of age determination by hard parts of 



albacore from Central North Pacific and 



Hawaiian Waters. U. S. Fish and Wildlife 



Service, Fish. Bull. 59(150): 

 Partlo, J. M. 



1955. Histological studies on albacore (Thunnus 



alalunga) gonads from the eastern Pacific. 

 Jour. Fish. Res. Bd. Can. 12(1): 61-67. 

 Schaefer, M. B. 



1948. Spawning of Pacific tunas and its implications 

 to the welfare of the Pacific tuna fisheries. 

 North American Wildlife Conference Trans. 

 13: 365-371. 



