234 



Fishery Bulletin 97(2), 1999 



10 



20 30 40 50 

 Age (R22) (years) 



Figure 6 



Mean hapuku age estimates of (A) reader 2 (R.^ j), and (B) 

 reader 1 (R, ). plotted against the ages determined for the 

 same fish by reader 2 (R., „). The data points are the means 

 and standard errors of the data shown in Figure 5. Diago- 

 nal lines indicate equality of age estimates. 



sus R22) (mean=18.0%, range=10.1-26.1%) than be- 

 tween readers (Rj versus R22' (niean=21.3'^, 

 range=12.6-31.4%). The CV declined shghtly with 

 increasing age for both the within- and between- 

 reader comparisons. 



The main differences between counts arose from 

 1) different band counts near the otoHth core (poten- 

 tial age differcnce=l-3 years), 2) different band 

 counts in an unclear central zone around bands 4-8 

 (several years), and 3) classification of the composition 

 of the otolith margin as opaque or hyaline (one year). 



The greatest estimated ages (mean of Rj. R., j and 

 R2 2> were 50.3, 50.7, 59.3, and 63.0 years, but few 



fish were found to be more than 20 years old (Fig. 5). 

 The youngest hapuku were 3 years old. The von 

 Bertalanffy growth curve fitted to R, data differed 

 little from that fitted to R2 2 data (Fig. 8A; Table 2). 

 Females grew faster than males, but the difference 

 was slight, and the overlap of data points was sub- 

 stantial (Fig. 8B; Table 2). The largest male was 134 

 cm, the largest female 147 cm (with three females 

 longer than 140 cm). 



Growth curves fitted separately to the northern 

 and central data were very similar (Table 2). Inspec- 

 tion of the residuals from the central curve again 



