FORK LENGTH-INCHES 



Figure 4. — Frequency distribution by 1-inch groups of 

 lengths of bluefin tuna taken July 1-15, by years. The 

 1953 sample includes 102 fish measured June 28-30. 



GROWTH OF BLXJEFIN TUNA 

 d 



60 



40 



20 















X 



iZ 100 



o 80 



S 60 



CD 



§ 40 



^ 20 





 40 



20 



















45 



NONE MEASURED |9 5 5 



in_^_g ,1956- 

 NONE MEASURED '9^7 



o4" 



I 



1 1 J 1 1 1 1 1 1 1 1 1 1 1 1 . 1 [ 1 1 1 1 



20 30 40 



FORK LENGTH-INCHES 



50 



Or--- 



if 



2_' ^ 1954 J 

 n 1955 



1956 

 1957 



I M M I I I I I I I 



' 10 



I I I M I I I I 



20 30 40 



FORK LENGTH-INCHES 



50 



FifiiTRE 5. — Frequency distribution by 1-inch groups of 

 lengths of bluefin tuna taken July 16-31, by years. 



Figure 6. — Frequency distribution by 1-inch groups of 



lengths of bluefin tuna taken August 1-16, by years. 



year is supported by tlie fact that no annuli are 

 found on scales and vertebrae of fisli of this size. 

 Moreover, it is in accord with the conclusions of 

 Sella (1929) and others studying the European 

 bluefin tuna, which were officially accepted by the 

 International Council for Exploration of tlie Sea in 

 1932 at Malaga (Conseil International pour I'Ex- 

 ploration de la Mer, 1933), and witli tliose reached 

 by Westman and Gilbert (1941), Westman and 

 Neville (1942), and by Rivas (1954), for bluefin 

 taken ofi' New York and Miami, Fla. It is sup- 

 ported by our failure in all our observations, in- 

 quiries, and searching of literature and records, 

 to find any evidence that a smaller size group 

 exists. We conclude therefor that tuna in the 

 second size group (corresponding to fish with 1 

 animlus) are 1 year old; in the third size group 

 (2 annuli) are 2 j'ears old; and so on through 4 



\ 



