392 
Fishery Bulletin 99(3) 
Table 1 
Detailed summary of data for pooled otolith age groups and single otoliths from Megalops atlanticus. Age range of age groups is 
based on annulus-derived age estimates. Capture dates and average fork length are listed for comparison. Age groups consisted of 
4 toll otolith cores and amounted to -1 g. Single otolith cores weighed close to 0.1 g. 
Age-group or 
single otolith age (yr) 
Capture date 
or range 
Fork length 
(mm ±SD) 
Number of 
otoliths 
Sample 
weight (g) 
Male 
2-4 7 
7 Mar-16 Oct 1989 
568 ±80 
7 
0.6786 
13 
22 Jun 1989 
1499 
1 
0.1129 
17 
4 Jul 1989 
1452 
1 
0.1124 
18-21 
1 May-25 Jul 1989 
1442 ±78 
10 
1.0498 
31-36 
12 Jun— 7 Jul 1990 
1532 ±73 
4 
0.3480 
32 
6 Jun 1989 
1588 
1 
0.1279 
32 
19 Jul 1992 
1620 
1 
0.1220 
Female 
3-4 7 
24 Jan-15 Jul 1989 
583 ±59 
9 
0.8775 
15-24- 
6 Jun- 12 Aug 1989 
1641 ±92 
11 
1.0718 
35 
4 Jul 1989 
1613 
1 
0.1002 
36 
12 May 1992 
1780 
1 
0.1331 
37 
12 Jun 1993 
1950 
1 
0.1167 
44 
2 Sep 1991 
2040 
1 
0.1366 
48-50 
20 Apr-20 Jun 1989 
1708 ±110 
4 
0.3314 
55 
4 Mar 1991 
2045 
1 
0.0884 
1 Whole juvenile otoliths. 
2 Ten otoliths ranging in 
age from 21 to 24 yr; one 15-yr-old otolith was 
erroneously included in this age group. 
Table 2 
Radiometric results for each Megalops atlanticus age group and single otolith samples. Activities are expressed as disintegrations 
per minute per gram (dpm/g). 
Age-group or 
single otolith age (yr) 
Sample 
weight (g) 
210 Pb (dpm/g) 
± % error 7 
226 Ra (dpm/g) 
± % error 2 
210 Pb: 226 Ra 
activity ratio 
210 Pb: 226 Ra 
low 
210 Pb: 226 Ra 
high 
2-4- 3 
0.6786 
0.005 ±6.7 
0.258 ±1.03 
0.017 
0.016 
0.019 
13 
0.1129 
0.043 ±12.1 
0.085 ±1.52 
0.507 
0.439 
0.577 
17 
0.1124 
0.035 ±13.6 
0.061 ±1.61 
0.568 
0.483 
0.656 
18-21 
1.0498 
0.072 ±3.4 
0.246 ±1.01 
0.292 
0.280 
0.305 
31-36 
0.3480 
0.094 ±5.3 
0.181 ±1.25 
0.520 
0.486 
0.555 
32 
0.1279 
0.031 ±13.5 
0.044 ±1.53 
0.712 
0.607 
0.821 
32 
0.1220 
0.265 ±6.0 
0.401 ±1.02 
0.663 
0.617 
0.710 
Female 
3-4 5 
0.8775 
0.003 ±5.7 
0.217 ±1.06 
0.015 
0.014 
0.016 
15-24 
1.0718 
0.059 ±3.9 
0.163 ±1.07 
0.362 
0.345 
0.381 
35 
0.1002 
0.119 ±8.2 
0.299 ±1.35 
0.397 
0.360 
0.435 
36 
0.1331 
0.086 ±8.5 
0.144 ±2.24 
0.597 
0.534 
0.663 
37 
0.1167 
0.126 ±8.0 
0.243 ±1.18 
0.518 
0.471 
0.567 
44 
0.1366 
0.113 ±7.4 
0.170 ±1.33 
0.667 
0.609 
0.726 
48-50 
0.3314 
0.148 ±4.5 
0.266 ±1.19 
0.555 
0.524 
0.587 
55 
0.0884 
0.086 ±12.2 
0.094 ±1.42 
0.909 
0.787 
1.035 
7 Calculation based on standard deviation of 210 Pb activity; Wang et al, 1975. 
2 Calculation based on TIMS analysis routine (±1 SE). 
3 Whole juvenile otoliths. 
