According to reports, the Pacific Society has contributed a certain 

 amount of survey expense funds to the Japanese Society for the Pro- 

 motion of Scientific Research in order to make a study of the spawn- 

 ing grounds of skipjack and tuna, and research on this important and 

 difficult problem is being carried on by the Tropical Biology Experi- 

 ment Station at Palau. Several years ago, Mr. Keizo Takahashi of the 

 Experiment Station was already conducting research on skipjack spawning 

 grounds. As a result of conducting artificial fertilization on mature 

 skipjack eggs which he collected from Palau waters, he was able to report 

 the verification of the assumption that the skipjack spawning groiind is 

 located somewhere in that area. 



The Celebes Sea linking the Philippines, Borneo, and Celebes was 

 considered the most promising area of investigation in the solving of 

 this problem. Recently I heard that Dr. Masamitsu Oshima, who was to 

 be dispatched to that area, was prevented by several circumstances from 

 going into the Outer South Seas area (TNt Celebes Sea area). After 

 arriving in Palau last April, he sailed southward from Palau aboard 

 the Zuiho Uaru and conducted a detailed investigation of the sea around 

 Helen Reef, Tobi Island, and l&lmahera Island. 



The Pan-Pacific Scientific Conference held in Canada the year before 

 last, assumed that the solution to this problem could be found generally 

 in the South Seas area. Since then, the fact that investigation and study 

 of the matter have been encouraged steadily in Japan has provoked great 

 interest among our circle, which has some connection with the matter, lie 

 must not be indifferent. 



The work of discovering the skipjack and tuna spawning grounds, 

 which is the most difficult problem of world fishery science, cannot 

 be accomplished overnight. Ifith all due respect for the efforts of 

 these researchers, we must do everything in our power to supply data 

 relative to this subject. 



At present, data obtained from tuna surveys are forwarded from 

 the scene of operations to the Tropical Biology Experiment Station as 

 the occasion arises and are being used to aid in their research. 



I hope that this material will aid in furthering the investigation 

 and research and that the research will be completed in the near future. 

 The day of completion will mark a new era in world fishery science. 



In our survey of tuna fishing grounds, the catch is immediately 

 eviscei-ated and thrown into the fish hold. Thus we have many opportunities 

 for observing the roe of the female fish. From our past experience it seems 

 that we have come in contact with a number of tuna with considerably matured 

 roe in various areas around the isleuads. 



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