catch rates are not correlated with latitude, but they appear to improve toward the center of the 

 Pacific. In the overall picture the bigeye is taken at a rate of about 0.5 fish per hundred hooks. 

 The species appears to be most abundant in Japanese waters from September to December. It 

 generally prefers to live at deep levels, however, it is not yet known with certainty exactly what 

 depth it prefers. As it has the habit of coming into the surface levels at night, it is sometimes 

 taken in drift nets and it is said that this occurs particularly often on nrioonlight nights. These 

 fish tend to be somewhat more abundant in tropical seas, and in both the Pacific Ocean jind Indian 

 Ocean areas they are taken in the proportion of about 10 percent of the yellowfin catch. 



4. Yellowfin tuna, Neothunnus macropterus (Temminck and Schlegel) 



This fish is also called gesunaga , hirenaga, kibire , and itoshibi. In the southern 

 Kyushu area when the word shibiis used, this species is meant. Jordan distinguished the yellow- 

 fin and the itoshibi, giving to the latter the scientific name Neothunnus itosibi, but this is thought 

 to have been clearly a mistaken interpretation of the characteristic morphological chjinges which 

 accompamy growth in this fish. 



Yellowfin are generally somewhat snnaller than bigeye tuna, attaining a length of 

 about 2 meters and a weight of around 70 kilograms. 



A characteristic of this fish is the length of the caudal portion, that is the part of the 

 fish behind the vent. In nriature fish the second dorsal and anal fins are remarkably elongated. 

 The names hirenaga and itosibi are expressive of this peculiarity. These fins and the finlets 

 which follow them are of a bright yellow color. The names kihada and kibire are based on this 

 characteristic. The pectoral fins are rather long, reaching to a point slightly back of the inser- 

 tion of the second dorsal. 



The color of the flesh is a rather pale red which looks extraordinarily bright to the 

 eye. In western Japan this fish is generally more highly regarded than the black tuna. When 

 eaten raw the flavor is rather faint, but it is particularly delicious during the summer. Besides 

 being consunned fresh, it is exported canned in oil and the scrap meat produced by the canning 

 operation is made into stew. The young fish are frequently taken in fixed gear or by pole and 

 line and are manufactured into the so-called shibibushi by the same methods used in making dried 

 skipjack sticks. 



o 

 The range of distribution extends from the Equator to about 35 N. latitude, but the 



areas in which this species is the object of a fishery are a comparatively narrow belt along the 

 Equator, and the series of enclosed waters comprising the South China, Sulu, and Celebes seas. 

 The yellowfin become more abundant in the North Pacific during the summer, and are most 

 numerous in the waters of the Ogasawsira Islands from June to July and in November. At that 

 time they are caught at a rate of about 1.5 fish per hundred hooks. They are taken, though ex- 

 tremely rarely, in the Sea of Japan. 



5. Koshinaga, Kishinoella rara (Kishinouye) 



Northern bluefin (Australia). 



This fish is also called bintsuke. In Formosa it was called the seiban maguro . This 

 is the smallest of the tunas, fish of about 70 centimeters long and weighing about 7 kilograms 

 being already mature. Dr. Kishinouye placed this fish in the same genus with the yellowfin tuna, 

 but it is given here as Kishinoella in accordance with the opinion of Jordan and Evermann, who 

 said that because of morphological differences it should be placed in a separate genus. According 

 to recently received reports, K. rara is a synonym of the northern bluefin, K. tonggol, which 

 has long been known in the coastal waters of Australia. 



34 



