568 
Fishery Bulletin 96(3), 1 998 
(male) - L J female) < 8.419, -0.026 <K( male) -K( female) 
<-0.020, -0.511 < £ 0 (male) - ^(female) < -0.344). 
Of the thirty otoliths too large for whole-otolith 
reading, ten were randomly selected, sectioned, and 
read, yielding ages of 15 years and above. The VBGF 
parameters computed from all available data, includ- 
ing whole-otolith and sectioned-otolith ages (n=1180) 
were considered to be representative of the popula- 
tion (asymptotic standard error): L ^ = 97.32 cm 
(1.816), K = 0.1111/yr (4.073 x 10- 3 )°°, t Q = -0.316 
(0.0569) (n=1180, P 2 =0.93). The asymptotic length 
was converted to an asymptotic weight of W. :> . = 10.84 kg. 
The growth performance of L. peru was (J> = 1.736. 
The age composition of the sampled males differed 
significantly from that of the females (Kolmogorov- 
Smirnov two-sample test, D=0.0843, 0.01<P< 0.05) 
(Fig. 6). 
Mortality 
The length range of most age groups was on the or- 
der of 20 cm (Table 4: Fig. 7A). Catch curves were 
constructed for males, females, and pooled sexes. 
Total mortality rates (Z) were calculated without the 
extreme age groups and those not fully recruited to 
the fishery (Fig. 8). Total instantaneous mortality 
rate for females, estimated from the catch curves, 
was significantly lower compared with those for 
males (£=-2.112, df=52,P«0.001). Hoenig’s formula 
should be applied to the maximum age of “the larg- 
est few fish” (Hoenig, 1983). On the basis of this 
recommendation and the fact that only one out of 
5690 fishes measured in this study was larger than 
90 cm, this 31-year-old fish was interpreted as an 
outlier and a t max - 26 years was considered more rep- 
resentative of the population. This value yielded a Z = 
0.172/yr, which is considerably lower than the catch 
curve estimates. The estimates of M obtained from the 
empirical relationships 0.222/yr (Pauly, 1980) and 
0.248/yr (Ralston, 1987) were compatible with the catch 
curve mortality estimates giving exploitation rates 
F/Z) ranging from 0.121 (females) to 0.393 (males). 
Discussion 
Sampled length range 
The accurate estimation of growth parameters depends, 
among other factors, on the adequate sampling of the 
length range of a species. The fish used in this study 
covered most of the known length range of the Pacific 
