55C 



Fishery Bulletin 100(3) 



600 -1 



500 



400 - 



500 



400 



300 



200 



100 



females 



LML=300 mm 

 LML=280 mm 



researcher caught 

 fisher caught 



males 



LML=300 mm 

 LML=280 mm 



13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 

 Age (months) 



Figure 2 



Lengths at age. beginning at 10 months, for Gulf St. Vincent King George 

 whiting of both sexes. The sohd line is the generalized seasonal von Ber- 

 talanffy mean length cui-ve lEq. 2) with t^, = fixed. Dashed lines indicate 

 confidence bounds as normal likelihood standard deviation (Eq. 3). Dots 

 represent individual obser\'ations of length-at-age. 



summer (December-February) for all data sets except 

 Gulf St. Vincent males. 



Estimated (likelihood maximum) and observed distribu- 

 tions of lengths-at-age were plotted for Gulf St. Vincent 

 females (Fig. 5) and males (Fig. 6). Because the estima- 

 tion likelihood was fitted to formulas for mean (Eq. 2) and 

 standard deviation (Eq. 3) of all ages at once, close fit to 

 the majority of individual length-at-age distributions in- 

 dicated a growth description mutually consistent among 

 ages and a satisfactory approximation to monthly lengths 

 at age overall. 



For younger ages (28-35 months), the sampled frequen- 

 cies were modeled by the truncated right-hand component of 

 the normal pdf The LML truncation lengths for each normal 

 curve (280 or 300 mm in Figs. 5 and 6) indicated the lower 

 limit of samples from the fishery. These samples are gener- 



ally well fitted (Figs. 5 and 6), suggesting these truncated 

 younger samples do contribute to the overall growth fit and 

 that the truncated likelihood is effective in describing the 

 monthly growth of the length-at-age cohort across LML into 

 legal sizes. One exception yielding a less close fit were female 

 fish aged 28 months taken under a LML of 280 mm (Fig. 5). 



Weight-at-length 



Parameter estimates for a and [i (Eq. 6) covaried strongly. 

 When all four parameters were allowed to freely vary, /3 

 differed little from 3.2 for all data sets (Table 4). Likeli- 

 hood-ratio tests were therefore carried out to determine 

 whether the model allowing p to vary freely yielded sig- 

 nificantly better fits than one with three parameters and 

 P fixed at 3.2. For all but Spencer Gulf males, likelihood- 



