Table 60 Size coinposition by months on 

 the Paiau fishing grounds 



Note? Pig-ores for April, May^ and June are 

 the average for 1935=-39| those for 

 October 5, November c, and December are 

 the average for 193U"1938o 



of the skipjack stocko If we seek the survival rates* from 

 the ratio of large and small fish for the Truk and Palau grounds 

 by the same method as was previously^/ followed with the black 

 tunaj yellowfin tuna, and albacore,, they come out as o58 and o50 

 respectivelyo On the other hand, in late autumn the only medium- 

 sized fish are those of age=group III and the large fish are of 



■jf 



8/ 



Since raedium-sized fish are I088 - 3o75 kg;, they include 



^"^t " "^°bO ^ "^^ °^ ^^® ^^""^ '^^^ ^^ si l k ° foki ^ """"^ °^ 

 age-group IVo The large-sized fish are those over 3«75 kgj, 

 so 1 - 0I3 " 087 of age-group IV and all of age-groups V and 

 up are included,, Consequently 5, taking /^ as the survival rate, 



.87 P ;^ PI n ir- . n^ V 



large _ I^ ^ and since this value is loU5 at Truk 



medium " o85 / 13p ^ 



and loOU at Palau, the values of f will be 0^8^ and =50j^s 



respectivelyo 



Tauchis Morisaburog On the Stock of Black Tunao Bull o Jap „ 

 Soco Scio Fisho 9 (U), I9UO5 On the Stock of Yellowfin W, 

 loco cite I On the Stock of Albacore, loco cite (Translated 

 in FWS Special Scientific Report = Fisheries Noo^l6 - Three 

 Papers on the Stocks of Tuna in Japanese Waters oj 



29 



