FISHERY BULLETIN: VOL. 79. NO. 3 



Table 2. — Modal progressions for skipjack tuna used to estimate fork length (centimers) at age. Modal progressions indicated by solid 



lines; n = 83. 



TABLE 3. — Modal progressions for yellowfin tuna used to estimate fork length (centimeters) at age. Modal progressions indicated by 



solid lines; n = 105. 



DISCUSSION 



The use of the von Bertalanffy function for es- 

 timating length-at-age impHes that this function 

 is a valid description of grov^h of skipjack and 

 yellowfin tunas and that growth of all groups of 



each species is identical. Kearney (1978) has 

 speculated that growth of skipjack tuna may be 

 better represented by a number of linear stanzas, 

 and an examination of the modal progression data 

 indicates a disparity in growth rates among 

 groups of fish. It should be noted that Knight 



528 



