In th« genus Thtauma this family approaches the Cyblidae* It has four genera, 

 the relationships of which are shoim below* 



First dorsal oontinuous with second dorsal, dorsal surface of skull dosed with 

 cartilage with one pair of foramina 



Hhole body covered with scales, two subeutemeous lateral vessels on each side 

 of the body olose'/ together, teetli on both Jaws and on the vomer, palatines, 

 and mesopterygoidf vert* 18/21 »o» Genus Thuzinus ( shibi-golcu ) 

 No scales except on corselet 



^o subcutaneous vessels on each side of the body, teeth only on the 

 iame, stripes on the belly, vert. 20 / 21 ••• Geniis Katsuwonus n»g« 



C^fttsuo-joku) 

 One subcutaneous vessel on each side, teeth in both Jaws and on the 

 Tomer and palatines, oblique or longitudinal markings on HtB back with 

 ■pots generally on Hm anterior pectoral region, vert* 20 / 19 •*• 



Genus Enthynntts ( yaito-toku ) 

 First dorsal not oontinuous with second dorsal, no~f oramen in the dorsal surface 

 of the skull, no scales except on the corselet, one subcutaneous vessel on each 

 side of the body, teeth in both Jaws only, oblique markings on the back, vert* 

 20 / 19 *** Genus Auxis (nejlka-y.oku ) 



Genus Thunnus (shibl-goku ) 



The first vertebra is very thin eoid is fused to the skull* Its neural spine 

 is separate* Siere are lateral projections on several of the thoracic vertebrae. 

 The fins are well developed, particularly in mature fish. The lateral line makes 

 a peculiar curve above the peotoz*al fin* The back is dark Indigo with a greenish 

 lustre posteriorly* The belly is gray with white spots and stripes* Bie fins are 

 sometimes yellowish* Most of these fishes are large-sised and form big schools* 

 They are timid* 



Five species are found in Japanese waters* Their relationships are as shown 

 below* 



The suboutaneoiis lateral vessels pass between the fifth and sixth vertebrae 

 PBctor«.l fin short not reaching second dorsal, no air bladder **• Th* 



orlentalis (kuroshlFl) 

 Pectoral fin very long reaching to second or third dorsal finlet, an air 

 bladder is present •** _^« alalunga? ( tomboshibi ) 

 The subcutaneous lateral vessels pass between the seventh and eighth vertebrae 

 Caudal vein does not connect directly with the Cuvierian duct, head and eye 

 are large •** Th* mebachl n*sp* (mebaohi ) 



Caudal vein connect* directly with the right Cuvierian duct, there are groups 

 of oapillarles below the spinal column 



Pectorals long reaching to second dorsal *** Th, macropterus (kihata ) 

 Iteotoral does not reach second dors&l *** Th* rarus n*Bp. (koshinaga ) 



ThunnitB orlentalis (kuroshibi ) 



Called gotoshlbl in Mlyacakl. 



D* 12 - 16, 14, 8 or 9 A* 13 - 15, 7 or 8. Gill rakers 12 / 24. 



This spedes is distinguished by the shortness of the pectoral and caudal fins, 

 the marked bend in the lateral line, the absenoo of an air bladder, and the dark 



