312 
Fishery Bulletin 1 1 1 (4) 
Otolith weight at age and gonad weight at length 
Nonlinear least squares estimation also was used to 
fit second-order polynomial functions to regional esti- 
mates of otolith weight at age t (in years) and an ex- 
ponential function to gonad weight ( Wq ) at FL (Lp in 
millimeters). 
The functions were defined with relevant starting 
parameters (a,b,c) by the following equations: 
Otolith weight = a + b it) + c ( t 2 ); (5) 
Gonad weight = e (a + b ^p' 1 . (6) 
Quantile-quantile normal plots and Cook’s Distance 
were used to identify outliers for exclusion, and plots 
of residuals were used to test for lack of homogeneity 
in variances. Comparisons in the 2 responses by sex or 
region were restricted to the range of explanatory data 
(sizes or ages) common to each level in the comparison 
with likelihood ratio tests for coincident curves and 
ANCOVA with type-III sums of squares. Log e transfor- 
mations were used to linearize the gonad weight and 
otolith weight covariates for the ANCOVA. Data from 
the Arafura Sea were too few for use in these tests and 
were compared visually with the other regions. 
Australian and international fishing records 
An Internet search for record sizes of John’s Snapper and 
other large lutjanids landed by line and spearfishing was 
conducted for countries in the Indo-West Pacific, but only 
world and Australian records were available. The 2011 
records maintained by the International Game Fishing 
Association (IGFA), Australian National Sportfishing As- 
sociation (ANSA), Australian Angler’s Association (AAA), 
and Australian Underwater Federation (AUF), were used 
60 
50 
40 
30 
20 
10 
0 
25 
20 
15 
10 
5 
0 
North Queensland 
n=216 
B 
Cape York 
n = 63 
Kimberley 
n = 568 
Gin. 
60 -i 
50 
40 
30 
20 
10 
^ ^ ^ 
V ^ ^ t? N ^ ^ <£> S eft' 
Fork length (mm) 
nni 
/?= 258 
Urn 
Number of annuli 
Figure 2 
The length- and age-frequency distributions of John’s Snapper (Lutjanus johnii ) sampled dur- 
ing the period of February 1989-April 2002 in 4 regions of Australia: (A) north Queensland, 
(B) Cape York, (C) Kimberley, and (D) Arafura Sea. The y-axes represent the numbers of fish. 
Lengths are fork lengths measured in millimeters, and age is measured as the number of an- 
nuli (annual growth rings) observed in sectioned otoliths. n=sample size. 
