Cappo et a\ A new approach to validation of periodicity and timing of opaque zone formation 



483 



2.0 



1.5 



Q-1.0 



O 



0.5 



A S1998 



S1978' 



IS1979 ' 

 • S1991 



si 947 



3S1949 



0.5 1.0 1.5 



Sum of initial and final fraction 



si 958 



964 



2.0 



Figure 8 



Number of increment cycles per year plotted against the sum of the initial ilFt 

 and final fractions iFF) measured along the ventral LI axis. Data labelled with 

 slide numbers have extra or fewer cycles than expected. Circled data on the 

 end of the line represents fish whose otolith growth in the final increment cycle 

 markedly exceeds the previous deposition rate. 



2r 



i5< 





< < < < < 



% 



b, % % % 



Figure 9 



Number of increment cycles per year along the ventral LI 

 axis estimated for 61 fish of nine study species with the 

 direct method. 



along the ventral axis (^0025 64=l-99' confidence interval 

 0.94</3<1.09) and /3=1.09 along the sulcal axis (^0025. 

 g2=1.99; confidence interval 1.02</kl.l6). The regression 

 residuals were normally distributed only along the ventral 



axis (n=66 w=0. 981428 P<w=0.7105), and were influenced 

 by a group of positive residuals around 1.5 years at liberty, 

 corresponding to V > 1 cycles/yr. These were mainly L. 

 erythropterus, for which Equation 6 consistently estimated 



