94 
Fishery Bulletin 109(1) 
Table 2 
Estimates for von Bertalanffy growth function parameters: growth coefficient ( K ), theoretical maximum length (L^), and 
theoretical age where length is equal to zero (t 0 ) (± standard error), sample numbers ( n ), age ranges, and adjusted R 2 values from 
different methods (observed [Obsv], category-adjusted [Adj-cat], formula adjusted [Adj-frm], back-calculation to all annuli [BC- 
all], and back-calculation to the last annulus only [BC-last]) for estimating length-at-age for Scomberomorus commerson and S. 
semifasciatus. 
Species 
Sex 
Method 
K 
L m (mm) 
t 0 (years) 
n 
Min age 
Max age 
^adj 
S. commerson 
Female 
Obsv 
0.16 (0.03) 
1508(153) 
-4.55 (1.02) 
288 
1 
15 
0.7592 
Adj-cat 
0.11 (0.03) 
1725 (173) 
-5.56(1.08) 
247 
1 
11 
0.7806 
Adj-frm 
0.10 (0.03) 
1735 (186) 
-5.86 (1.18) 
239 
1 
11.9 
0.7821 
BC-all 
0.51 (0.03) 
1248 (13) 
-0.39(1.06) 
811 
1 
10 
0.8473 
BC-last 
0.45 (0.05) 
1273(25) 
-0.68 (0.15) 
216 
1 
10 
0.8603 
Males 
Obsv 
0.21 (0.06) 
1186 (109) 
-5.77(2.64) 
213 
1 
11 
0.8396 
Adj-cat 
0.20(0.06) 
1202(55) 
-5.25 (1.58) 
187 
0.5 
11 
0.5715 
Adj-frm 
0.21 (0.06) 
1186 (47) 
-5.18(1.52) 
187 
0.8 
11 
0.586 
BC-all 
0.75(0.05) 
1047 (9) 
-0.18 (0.07) 
601 
1 
9 
0.588 
BC-last 
0.74 (0.09) 
1063 (15) 
-0.27 (0.15) 
157 
1 
9 
0.8168 
S. semifasciatus 
Female 
Obsv 
0.29 (0.06) 
896 (22) 
-4.08(0.78) 
306 
0 
9 
0.555 
Adj-cat 
0.23(0.06) 
938 (38) 
-4.64 (1.13) 
310 
1 
9 
0.5371 
Adj-frm 
0.20 (0.06) 
929 (41) 
-5.40(1.44) 
306 
0.6 
9 
0.4937 
BC-all 
1.04 (0.05) 
827 (6) 
0.19 (0.04) 
923 
1 
9 
0.8243 
BC-last 
0.99 (0.07) 
834(8) 
0.15(0.07) 
289 
1 
9 
0.797 
Males 
Obsv 
0.31 (0.04) 
840 (13) 
-3.87 (0.43) 
323 
0 
10 
0.7049 
Adj-cat 
0.34(0.04) 
845 (14) 
-2.86(0.43) 
325 
0.5 
10 
0.6822 
Adj-frm 
0.28 (0.04) 
847 (16) 
-3.77 (0.54) 
323 
0.5 
10.6 
0.661 
BC-all 
1.04 (0.05) 
781 (5) 
0.14 (0.04) 
974 
1 
10 
0.8262 
BC-lLast 
0.98 (0.07) 
785 (6) 
0.08(0.07) 
300 
1 
10 
0.8268 
Table 3 
Chi-squared values for the overall likelihood ratio test between growth estimates from different methods (category adjusted [Adj- 
cat], formula adjusted [Adj-frm], back-calculation to all annuli [BC-all], back-calculation to the last annulus only [BC-lLast], 
and observed [Obsv]) for estimating length-at-age for Scomberomorus commerson and S. semifasciatus (* indicates significant 
difference at P<0.005, Bonfferoni-adjusted a for multiple comparisons, df=3). 
Species Sex 
Method 
Adj-frm 
X 2 
BC-all 
* 2 
BC-lLast 
it 2 
Obsv 
X 2 
S. commerson Female 
Adj-cat 
1.2 
197.1* 
114.9* 
9.2 
Adj-frm 
162.6* 
101.0* 
13.6* 
BC-all 
10.4 
464.9* 
BC-last 
229.9* 
Male 
Adj-cat 
0.575 
158.3* 
80.8* 
5.4 
Adj-frm 
161.6* 
86.0* 
8.1 
BC-all 
12.0 
496.7* 
BC-last 
240.6* 
S. semifasciatus Female 
Adj-cat 
7.7 
172.9* 
167.3* 
16.3* 
Adj-frm 
139.8* 
147.7* 
23.7* 
BC-all 
0.546 
524.8* 
BC-last 
350.9* 
Male 
Adj-cat 
16.6* 
169.2* 
174.4* 
55.8* 
Adj-frm 
102.9* 
136.8* 
43.6* 
BC-all 
0.37 
561.7* 
BC-last 
434.0* 
