NOTE Grana-Raffucci and Appeldoorn: Age determination of larval strombid gastropods 
861 
Table 3 
Variability in statolith increment counts within laboratory-reared larval Strombus gigas. Age = days after hatching. 
Age 
(d) 
Statolith A 
Statolith B 
Counts 
Mean 
SE 
Counts 
Mean 
SE 
1 
2 
3 
1 
2 
3 
0 
6 
6 
6 
6.00 
0.00 
6 
6 
7 
6.33 
0.58 
0 
8 
8 
7 
7.67 
0.58 
8 
8 
7 
7.67 
0.58 
0 
7 
7 
7 
7.00 
0.00 
7 
6 
7 
6.67 
0.58 
(average) 
6.89 
0.78 
6.89 
0.78 
1 
8 
7 
7 
7.33 
0.58 
8 
7 
6 
7.00 
1.00 
1 
8 
7 
7 
7.33 
0.58 
9 
8 
7 
8.00 
1.00 
1 
7 
8 
7 
7.33 
0.58 
8 
8 
8 
8.00 
0.00 
(average) 
7.33 
0.50 
7.67 
0.87 
2 
8 
6 
7 
7.00 
1.00 
7 
7 
7 
7.00 
0.00 
2 
7 
7 
6 
6.67 
0.58 
7 
6 
7 
6.67 
0.58 
(average) 
6.83 
0.75 
6.83 
0.41 
3 
7 
7 
6 
6.67 
0.58 
7 
7 
7 
7.00 
0.00 
5 
11 
11 
11 
11.00 
0.00 
11 
11 
11 
11.00 
0.00 
5 
10 
11 
10 
10.33 
0.58 
10 
10 
11 
10.33 
0.58 
(average) 
10.67 
0.52 
10.67 
0.52 
6 
13 
15 
13 
13.67 
1.15 
12 
14 
14 
13.33 
1.15 
6 
10 
11 
11 
10.67 
0.58 
11 
12 
12 
11.67 
0.58 
(average) 
12.17 
1.83 
12.50 
1.22 
7 
14 
14 
12 
13.33 
1.15 
14 
12 
11 
12.33 
1.53 
7 
12 
12 
12 
12.00 
0.00 
12 
13 
13 
12.67 
0.58 
7 
14 
16 
15 
15.00 
1.00 
16 
13 
14 
14.33 
1.53 
(average) 
13.44 
1.51 
13.11 
1.45 
9 
18 
17 
15 
16.67 
1.53 
16 
20 
16 
17.33 
2.31 
9 
16 
15 
17 
16.00 
1.00 
16 
18 
16 
16.67 
1.15 
9 
14 
14 
14 
14.00 
0.00 
13 
15 
13 
13.67 
1.15 
(average) 
15.55 
1.51 
15.89 
2.20 
10 
16 
18 
17 
17.00 
1.00 
20 
20 
19 
19.67 
0.58 
Table 4 
Nested ANOVA of statolith increment counts for subsamples of laboratory-reared larval Strombus costatus and S. gigas. SS = 
sum of squares, df 
= degrees of freedom, MS = mean square, P = probability of error, S = 
P < 0.05, NS = P > 0.05. 
Source 
SS 
df 
MS 
F-ratio 
P 
Strombus costatus: 
Among age groups 
6,868.3 
7 
981.2 
103.3 
P<0.05 S 
Among individuals 
171.5 
18 
9.5 
5.3 
P>0.05 NS 
Between statoliths 
68.1 
37 
1.8 
0.2 
P>0.05 NS 
Within statoliths 
1,063.4 
123 
8.7 
Total 
8,171.3 
185 
44.2 
Strombus gigas: 
Among age groups 
6,732.5 
8 
841.6 
195.7 
P<0.05 S 
Among individuals 
81.7 
19 
4.3 
10.8 
P>0.05 NS 
Between statoliths 
14.1 
39 
0.4 
0.7 
P>0.05 NS 
Within statoliths 
74.8 
119 
0.6 
Total 
6,885.2 
185 
37.2 
