FISHERY BULLETIN: VOL. 84, NO. 3 



Figure 5.— Mean observed and back-calculated 

 lengths for year class of Netuma barba (* P < 

 0.05). 



| 500 



h 400 

 o 



y 300 

 < 200 



O 



•- 100 



.-^1*-* 

 -*-~ 



.-3P* 



S* 



S 



-+■ BACK-CALCULATION 

 -OBSERVED DATA 



I 'I I I T I" 



I 2 3 4 5 6 7 8 9 10 II 12 

 ESTIMATED AGE 



40 

 20 



40 

 20 



40 

 20 



40 

 20 



1 st HYALINE ZONE 2 nd HYALINE ZONE ESTIMATED AGE 



'\. 



/ 



/ 



\ 



f I * f I "^^^T" 



/ 



n- II 



n-19 



T  T »  



V 



r-£ 



n»20 



40- 



v 

 o 



2 

 UJ 



2 20 



cc 



b. 



UJ 



° 40 



Z^y\ 



v 



n=34 



■i r-  i" 1 



/ 



/• 



S 



r 



\ 



./ 



. — ■- 



n-206 



2 

 UJ 



cc 



20 



40 

 20 



40 

 20 



/ 



/' 



/ 



\ 



n*l36 



: /v 



r 



/ 



\ 



V 



n-126 



VL 



\. 





\ 



n«94 



40' 

 20 



vx 



I * I 



n«!8 



10 



12 



30 70 90 110 130 90 110 130 150 170 190 210 



TOTAL LENGTH (mm) 



Figure 6.— Back-calculated lengths frequencies at first and second hyaline zones 

 for year class of Netuma barba (n = number of specimens). 



thermore, as the modes for each year class are 

 similar, age determination can be considered 

 consistent. 



Validation of Age 



Validation of the otolith method for aging Netuma 



684 



