iieight groups are thought to have been respectively 187 cm, 210 cm, and 232 cm. 

 Consequently these three groups probably belong to the classes of eit;hth-yoar, 

 ninth-year, and tenth-year fish respectively. The fact that the modes of the 

 weights and lengths are near the lower limits of the range for the reepective 

 age classes can probably he explained by the season at irtiich the fish were 

 taken. Eighth-year fish were 3%, ninth-year fish were ^9%, and tenth-year fish 

 were 20% of the total catch. The percentage of eighth-year fish does not vary 

 greatly throughout the sfeason, but the ninth-year fish are most num-arous during 

 the peak of the season, and the tenth-year fish are rather plentiful only at 

 the beginning of the season. 



Table 5 Vteight groups of black tuna landed at Aburatsu from late 



January to May, 1937 



Kimura^^) sought to discover the rate of growth of the black tuna from the re- 

 sults of mor phone trie investigations of fish taken on the Omodora fishing 

 ground in Shlzuoka Prefecture. The size and weight ranges irtilch he found for 

 specimens in the age classes from fish of the year to fish in their fourth 

 year agree in general with the author's results, but for age classes above the 

 fourth year his results are greatly in error. 



II. lellowfin Neothunnus macron terus (Temminck & Schlegel) 



In June of 1937 four STr.all /ellowfin landed at the Numazu market and two 

 large yellowfin purchased at the Tokyo market were obtained, and age determina- 

 tions were made. The yellowfin has 38 vertebrae, of which the five from No» 5 



(2) Kimura, Kinosuke; Bull, Jap. Soc, Scientific Fisheries 1(1), 1932, 



