Sipe and Chittenden: A comparison of calcified structures for aging Paralichthys dentatus 
635 
were positive (Table 5). All regressions were again 
strong, with 100 r 2 values from 83% to 86%. 
Discussion 
Comparative evaluation of sectioned otoliths 
Our findings indicate that sectioned otoliths are 
the best structure for aging summer flounder over 
the age range 0 to 10 years. Sectioned otoliths had 
the shortest reading times, the highest confidence 
scores, the highest within- and between-reader 
agreement, and they were consistently clearer and 
easier to read than whole otoliths, scales, and oper- 
cular bones. These findings are new for summer 
flounder because no published studies have used 
sectioned otoliths to age this species. These findings 
generally agree, however, with many studies on 
other species that have found sectioned otoliths to 
be the best aging structure (for examples, Beamish, 
1979; Chilton and Beamish, 1982; Beamish and 
McFarlane, 1983; Lowerre-Barbieri et al., 1994). 
Right sectioned otoliths were generally superi- 
or to left sectioned otoliths. Although we found 
high agreement in age between right and left sec- 
tioned otoliths, right otoliths were much easier 
to prepare, and they had a larger counting path, 
which made it easier to identify the marks, result- 
ing in shorter reading times, higher confidence 
scores, and higher reader agreement. 
Although we have found sectioned otoliths to 
be the best structure for determining the age of 
summer flounder, our studies have not proven 
their accuracy. To do so would require known-age 
methods or at least marginal increment meth- 
ods. However, until validation is done, we feel 
there is sufficient evidence to recommend that 
sectioned otoliths replace the current practice of 
using scales for aging summer flounder. 
Comparative evaluation of whole otoliths 
Our findings indicate that whole otoliths are the 
second best structure for aging summer flounder 
over the age range of 0 to 10 years. Whole oto- 
liths had no preparation time and had the second 
shortest reading times, the second highest confidence 
scores, the second highest within- and between-reader 
agreement, and the highest agreement with sectioned oto- 
liths. Whole otoliths were generally easy to read in fish 
less than age 4 or 5, and we feel they are adequate for 
these younger ages, especially in large-scale production 
aging where preparation time is important. 
We found that the right whole otolith was often easier to 
read than the left when the secondary counting path was 
used. Therefore, although former studies have used the 
left whole otolith only (Poole, 1961; Eldridge, 1962; Smith 
and Daiber, 1977; Powell, 1982), we suggest that the right 
should be included in future work. 
Our findings on preparation and reading times, confi- 
dence scores, within- and between-reader agreement and 
agreement with sectioned otoliths are generally new be- 
cause the literature has not reported detailed evaluations 
of whole otoliths in summer flounder. Given our findings, 
we do not agree with the current preference for using 
scales rather than whole otoliths in summer flounder. In- 
deed, we disagree with the original reasons for rejecting 
otoliths, which included 1) poor calcification and poor con- 
trast between opaque and translucent zones (Shepherd, 
1980; Smith et al., 1981; Dery, 1988), 2) obscurement of the 
first mark as the fish ages (Powell, 1982), 3) deviation from 
the generalized pattern of opaque and translucent zone for- 
