COMPARATIVE STUDY OF SCOMBROID FISHES. 
387 
Aomori-ken. This specimen is nearly tlie same as the preceding one, but it 
is a little broader. 
An immature fish of Acardhocybium solandri, 27 cm. in the total length, 
was caught off Daicsaki, Miye-ken, in September 1917. It has about twenty 
transverse bands. Those in the precaudal region fade away near the ventral 
median line, but in the caudal region they are manifest from the back to the 
ventral median line. 
The growth of tunnies seems to be very rapid. The common tunny, 
Thunnus orientalis, most probably reaches maturity in the third year of age. 
Thmms orientalis, ca 22 cm in the total length, is the smallest specimen I 
have seen. It lias ten to fifteen faint transverse bands which fade toward the 
ventral median line. These transverse bands are divided into two at the 
ventral part. Such small individuals are found in August and in September. 
Some of them grow to a length of 30 cm or more. By next spring they 
grow to a length of ca 60 cm (fig. 43). When two years old they are about 
one metre in length and eleven kg. in weight. Three years old fish is con¬ 
sidered to weigh about fifteen kg. The growth of Thnnnus germo and Neothunnus 
Fig. V. Euthijnnus yaito (immature).;2/3.' 
