In outer appearance this fish closely resembles young yellowfin and is difficult to 

 distinguish from them, but the color of the flesh is a great deal paler than in the yellowfin, being 

 nearly white. The back is bluish-black, the belly is greyish white, and like the young stages of 

 other tunas, it has oblique rows of long and narrow colorless dots, which may appear grey de- 

 pending upon the angle at which they are seen. The second dorsal and the anal are not prolonged 

 into filaments. The finlets are yellow as in the yellowfin but are edged with black. The pectoral 

 fins are rather long, reaching to a point somewhat behind the insertion of the second dorsal fin. 



The flesh is pale red, almost white, and when served as sliced raw fish, it has a 

 very beautiful appearance and a very fine flavor. It is particularly delicious during the summer. 

 This species is rare in Japan, being taken by trolling during the winter off the south coast of 

 Kyushu. It is a great deal more coastal in character than the other tunas, and is common in the 

 vicinity of small islsinds in the tropics and sub-tropics. In Formosa it is taken throughout the 

 year by trolling, and is particularly abundant from Februziry to March and around August. 



The above five species are all of the tuncis that occur in Japanese waters. The 

 koshinaga is entirely without significance as an element in the tuna longline catch. 



B. Spearfishes 



As with the tunas, a great number of species of spearfishes have been reported from 

 various parts of the world, the number being actually in excess of 30 species. It is, however, 

 very doubtful whether so many species really exist. The reason that such a large number of 

 species have been reported is probably that these fish are difficult to study and there has been 

 no thorough comparative study made. 



The writer has some new opinions considering the classification of the spearfishes, 

 but as these will be published elsewhere, the notes given here are based on the hitherto accepted 

 classification. 



1. Shortnosed spearfish, Tetrapturus angustirostris (Tanaka) 



? angustirostris = belone = brevirostris 



This fish is also called sanmakajiki. It is the smallest of the spearfishes and rarely 

 surpasses a length of about 2 meters and a weight of about 20 kilogranns. It is easily distin- 

 guished fronn other species by such remarkable characteristics as the shortness of its lanceolate 

 upper jaw, the height of the central portion of its dorsal fin, and the absence of markings on the 

 sides of its slender body. 



The flesh is of the so-called "spearfish color" but rather pale, and although it has a 

 beautiful appearance when served as sliced raw fish, it is lacking in fat and is not very well 

 flavored. 



This is a remarkably pelagic species, and it appears not to occur in coastal nor in 

 enclosed seas. In Japanese waters it occurs in the open sea south of 35 N. latitude, but its 

 density of distribution is not very high. It occurs rather densely in the waters east of Formosa 

 amd the Philippines from Novennber to January, at which season it spawns. Up to the present it 

 has not been of great importcince to the fishery. The name angustirostris was given to this 

 species by Dr. Shigeo Tanaka, however, this is probably the same species as that reported fronn 

 the Atlantic Ocean under the name of belone and from the Indian Ocean as brevirostris. 



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