MacNair et al.: Age, growth, and mortality of Paralichthys californicus 
595 
Table 5 
Female California halibut total length versus age (mostly whole otoliths, some sectioned) 
in central California. 
TL (mm) 
Age (yr) 
Mean age 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
201-225 
0.0 
226-250 
0.0 
251-275 
1 
2.0 
276-300 
3 
4 
2.6 
301-325 
5 
7 
2.6 
326-350 
2 
10 
2 
3.0 
351-375 
1 
7 
2.9 
376-400 
8 
5 
3.4 
401-425 
3 
2 
3.4 
426-450 
2 
6 
3.8 
451-500 
1 
3 
2 
4.2 
501-525 
7 
2 
4.2 
526-550 
2 
1 
3 
4.2 
551-575 
1 
3 
1 
4.0 
576-600 
1 
2 
2 
1 
4.5 
601-625 
1 
4.0 
626-650 
1 
1 
0 
0 
1 
6.7 
651-675 
1 
1 
4.5 
676-700 
1 
0 
1 
1 
1 
6.3 
701-725 
1 
0 
0 
1 
6.5 
726-750 
3 
5.0 
751-775 
1 
0 
1 
6.0 
776-800 
1 
6.0 
801-825 
1 
4.0 
826-850 
1 
8.0 
851-875 
1 
9.0 
876-900 
1 
1 
8.5 
901-925 
1 
2 
8.7 
926-950 
0.0 
951-975 
1 
10.0 
976-1000 
0.0 
1001-1025 
1 
12.0 
1026-1050 
1 
12.0 
Mean length 
000 
313 
373 
493 
606 
672 
726 
810 
842 
970 
000 
1027 
000 
Median length 
of distribution 
444 
mm TL 
em California were 0.40 (95% confidence interval=0.34, 0.46) 
for males and 0.51 (95% confidence interval=0.45, 0.57) for 
females. Estimated annual mortality rates, A, were 0.60 for 
males and 0.49 for females. Instantaneous mortalities, Z, 
were estimated at 0.91 for males and 0.68 for females. We 
were unable to calculate survival rates and mortalities for 
central California halibut because the sample sizes were too 
small. 
Discussion 
The California halibut can be a long-lived species, living 
as long as 30 years (Frey, 1971; Pattison and McAllister, 
1990). However, none of the fish in our study was older 
than 13 years, and most of the fish were less than 11 years 
old (Fig. 5). We feel that the low average percent error in 
our study showed that both whole and sectioned otoliths 
were reliable methods for aging California halibut for the 
age range of our study. 
Pattison and McAllister (1990) suggested that because 
of the asymmetrical growth of the sagittae in larger fish, 
ages assigned to older fish (age 11 or older) may be un- 
derestimated if whole otoliths, rather than sectioned oto- 
liths, were read. Manooch and Potts (1997) in a growth 
study of greater amberjack also did not find whole oto- 
liths useful in aging fish. In contrast, we found that age 
estimates from whole and sectioned otoliths were not sig- 
