diet and also Indicate that the food varies with the locality. For exaII^)le■ during the 

 migration Into the more northern locallltles the food conelete moetly of email herring, cod, 

 and aardlnes. 



7. IconoBJo 



The 'black tuna le held in much esteem by the Japanese and Is mainly eaten raw. 

 The fleeh le daric red and is best during the cold months of the year. Immature two-year- 

 olds, Icnown as "Deji", eire conslclered a delicacy. 



AXBACOBE 

 ThunnuB germo (Lacepede; 

 Blncho, Blnnaga, Tombo-ehlbl 



1. General 



Literature records show that as early as the beginning of the 19th Century the 

 Japanese took the albacore Incidentally while fishing for other tunas. Since the flesh of 

 the albacore is soft and is considered ui^alatable as "saehlml" (raw fish), the traditional 

 manner in which the tunas are eaten, the fishermen avoided catching the species by placing 

 long lines at a depth more suitable for taking other tunas. 



In recent years, however, a large expoirt market for the alljacore was created when 

 the demand for canned white-meat tuna developed in the United States. During the decade 

 from 1930 to 1940 Japanese fishermen conducted intensive pelagic fishing for this species. 

 Special long line gear in vhlch more branch lines could be used were constructed for the 

 capture of the albacore, and the prewar years saw the Japanese extending their operations 

 into the distant waters to the east of Honshu and as far off as Midway Island. 



2. Diagnostic Characteristics 



The ailhacore (Figure 9) is sharply characterized ty the saher-sha^ed pectoral fin 

 which extends beyond the last rays of the dorsal and euaal fins to about the first flnlet. 

 This feature makes identification of the species almost always certain, and fishermen, 

 recognizing its distinctiveness, have naoed the fish "tombo-shlhi", meaning dragonfly tuna. 

 Other distinguishing characteristics are the second dorsal fin hlf^har than the first, and 

 the fact that the 'body is more slender than that of other species of tuna*. Other character- 

 istics agree with those of the species coi^rislng the genus Thunnus . For this reason 

 Eishlnouye (1923, p 434) discontinued the use of the generic name Oermo for the al'bacore 

 and included the species in the genus Thunnus . remarking that too much stress was placed on 

 the single character of the long pectoral. Farther investigations are necessary to clarify 

 the status of the albacore, although most authors agree the Paclflo forms are a single 

 species. 



The color is blackish blue on the back with a greenish luster towards the caudal 

 fin. The sides and the belly are silvery. The first dorsal is nearly colorlese but with a 

 dusky borderi the pectorals are black, the ventrale and the second dorsal dusky, and the anal 

 nearly colorless. The dorssd flnlets are dusky with a yellowish flush, aiid the ventral fin- 

 lets are dusky. In young specimens, about 60 centimeters in length, five or six dark, irreg- 

 ular longitudinal bands run near the ventral median line. They become more distinct on the 

 caudal region. The bands are more or less united in the form of an irregular network, 



3. Distribution and Migration 



Since the albacore has only recently assumed a position of li^ortance in Ja4>anese 

 pelagic fishing operations, information concerning its migrations and life history is in the 

 initial stage of investigation. The rapid development of intensive commercial operatioas 

 has yielded many catch records, however, and the Important fishing grounds in the western 

 Pacific are well known. The albacore is truly an oceanic fish, for the areas of greatest 

 abundance are in the offshore waters. kX some places it i^iproaches close to the Jv&Bese 

 ooaat bat does not enter shallow water. 



Zk 



p-6307 



