Generally the fish are extremely large and those taken early in the 

 season are commonly over 300 kgj, but with the passage of time the fish 

 gradually become smaller and those taken in the latter part of the season 

 are mostly around 150 to 200 kgo These are markedly larger than those 

 taken along the coast of Japan proper j where they would be considered on 

 the large sldco 



Considering the size of the fish^ the season of their migration, and 

 the state of maturity of their gonads, it is probably correct to regard 

 the black tuna which come into Formosan waters as separate from the schools 

 which move northward off the coasts of Japan proper. In recent years we 

 have data from which it is inferred that this species also occurs in the 

 Indian Ocean area,, They are also taken occasionally in Hawaiian waterSo 

 If we take into consideration all of these facts, probably the belief held 

 hitherto that this species occurs only in fairly northerly regions needs 

 to be corrected o 



(b) binnaga £ albacore, T<, 



The pelagic character of this species is extremely marked^, and the 

 fish do not come in close to the coast very much. Ordinarily they are 

 taken with longlines especially designed to fish for this specieSj but they 

 are also taken sometimes on longlines used for yellowfin, and the catch 

 from the areas under the South Seas Government=General contains a mixture 

 of about 1 per cent of this species^ At Takao in Formosaj too, the land- 

 ings of this species amount to lOpOOO j^n. or more per year, the fishing 

 grounds being almost entirely limited to the northeastern part of the 

 South China Sea and particularly the southern part of the Taiwan Straito 

 The fishing season is during the northeast monsoono 



Except for this area there is no record of its capture in the rest of 

 the South China Sea, the Sulu Sea, the Celebes Sea, or the sea areas 

 connected with the Banda and Flores seaso 



Since the fishing gear is not especially designed to catch this 

 species, but rather to fish for yellowfinj, we cannot decide unqualifiedly 

 that the albacore does not occor because of the above-mentioned lack of 

 records of its capture, however, in the South Seas Government-General and 

 in the northern part of the South China Sea a certain number of these fish 

 are taken on the same kind of gearo Therefore we can assume that in these 

 areas where there are absolutely no records of its Capture, the distribu- 

 tion of this species is either extremely sparse or else it does not occiir 

 at alio In other words,, "such enclosed seas are not suitable habitats for 

 this species. Before the war this remarkably pelagic species was taken 

 abundantly in the Midway area, 



(c) mebachi / big-eyed tuna, P., mebachi / 



Quantitatively this species is not as abundant as the yellowfin, 

 but it is widely distributed throughout the warm seaSo The northern 

 limit of its distribution is said probably to be about 36°N and its range 

 of water temperatures is taken to be 13° - 25^^o It is notably pelagic 



17 



