yellow in coIoto The dorsal sides of the pectorals are black and their 

 ventral sides are grayc Their tips are at times touched with yellow. 

 The vSntral fins are gray with yellow tips, the anal fin is white and 

 its tip is yellowo The anal f inlets are grayish white with their edges 

 more or less tinned with yellowc, 



The flesh is pink and rather soft, and is considered to be 

 rather inferior eating as raw fish. This fish is thought to occur at 

 the deepest levels of any of the tunaso It is believed that the 

 vertical distribution differs markedly as between night and day, the 

 fish coming into shallower layers at nighto The range of water tean- 

 peratures in which they occur is thought to be 13° - 28° Co j, and they 

 extend somewhat farther south than the black tuna and the albacore^ 

 while the northern limit of their distribution is supposed to be in 

 the vicinity of 40° N<, As they are an offshore sriecies they do not 

 occur in the Japan Sea^ and in the south em seas they are scarce in 

 enclosed sea areas and more numerous in the open oceanc 



They attain a length of about l.,5 mo and a weight of 80 kgo £, 

 and are tVie next largest species in size to the black tunao 



Meothunnus Kishinouyep 1923 



The cutaneous blood vessel passes through the myotome of the 

 seventh vertebrae The posterior cardinal vein joins the right Cuvierian 

 ducto There are plexuses of srnall blood vessels in the haemal canalo 

 Clusters of small blood vessels are completely absent from the surface 

 of the livero The vertebrae of the caudal r egion are elongated^, and 

 consequently even when viewed from outside the caudal region is longo 

 The pectoral fins are long and reach to a point beneath the posterior 

 edge of the first dorsal or even farther posteriorlyo All of the fin- 

 lets are yellowc Some individuals have air bladders and some lack themo 



Jordan and Hibbs in 1924 separated from the species of this 

 genus those which do not have air bladders and set up the new genus 

 Kishino ellao 



There are thought to be two or three species occurring in 

 Japanese waters ^ but there has not been sufficient study of them as 

 yeto 



Key to the species s 



(1) An air bladder is presento Number of gill-rakers 

 9 / 12 s 30, Pectorals long with their tips extending 

 past the posterior edge of the first dorsal baseo In 

 mature fish the second dorsal and anal are remarkably 

 long o3..o..oooo(jo.«ooooooooooooo«ooot> macropterus 



(2) No air bladdero Number of gill-rakers 6 / 17 s 23^ 

 Pectorals shorty their tips reaching to the vicinity 



of a point beneath the posterior edge of the first dorsal 



31 



