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Fishery Bulletin 96(3), 1998 
(BFE) and TL, gutted body weight (GBW), and age. 
Total length was the best predictor of batch fecun- 
dity (Fig. 5; BFE = 1.773 x 10 3 (TL) - 1.119 x 10 6 ; 
r 2 =0.600, P<0.0001, n=39); followed by GBW ( BFE - 
5.942 x 10 4 (G£W) - 9.517 x 10 4 ; r 2 = 0.576, P<0.0001, 
n= 35); then age ( BFE = 9.476 x 10 4 (age) - 1.213 x 
10 5 ; r 2 =0.474, P<0.0001, n=38). 
Spawning frequency: by year, and age x year 
Spawning frequency estimates were determined for 
females >709 mm TL in 1991, >576 mm TL in 1993, 
and >669 mm TL in 1994. Variations in spawning 
frequency were significantly different among years 
tested (/-test, P<0.02). Spawning frequency for fe- 
males in 1991 was 27 times, with 29.3% (93/317) of 
individual females spawning at an average of every 
3.4 d. Spawning frequency was not determined in 
1992 owing to the absence of samples from January 
and February. Spawning frequency in 1993 was 14 
with 16.1% (36/224) of individual females spawning 
at an average of every 6.2 d. Spawning frequency for 
1994 was 8 with 14.0% ( 18/129) of individual females 
spawning at an average of every 7.2 d. 
Spawning frequency also varied significantly 
among ages (/-test, P<0.01) and by age x year 
(ANOVA, P<0.05) for gag (n >5 per age x year) 
(Table 3; Fig. 6). Age-2 females in 1993 had a 
spawning frequency = 0, although one spawn- 
ing female of this age occurred in 1994. Age-3 
females in 1991 also had a spawning frequency 
= 0; 1993 and 1994 spawning frequencies were 
also low (6 and 7, respectively). Spawning fre- 
quency varied the most (6-71) among years for 
4- to 8-yr-old gag. Nine year old gag spawned 41 
times in 1991. All sample sizes for 10- to 12-yr- 
old, 16-yr-old, and 26-yr-old gag were inadequate 
(n<6) for estimation of spawning frequency. 
Annual fecundity 
Annual fecundity estimated with spawning fre- 
quency estimates by age and year ranged from 
0.065 to 61.4 million (Table 4; Fig. 7). Only 
spawning frequencies for aged fish (n>5 per age 
and year) were used. Age was an effective pre- 
dictor of annual fecundity (AFE= 9.276 x 
10 3 (age) 3 - 94 ; r 2 = 0.76, P<0.0001; n= 33). 
Discussion 
We found both the peak and maximum length 
of the spawning period for gag to be slightly 
longer than previously determined (e.g. 
McErlean, 1963; Hood and Schlieder, 1992; 
Coleman et ah, 1996; Koenig et ah, 1996) in the 
Gulf of Mexico. Both GSI and percent frequency 
of hydrated oocytes and POFs were greatest in 
February through April, but a few POFs were 
present in December-January and May-July. 
Our sampling may not have included peak 
spawning from 1992 through 1994, as it had in 
1991. McErlean (1963), through macroscopic 
examination of gonads, estimated that spawn- 
ing occurred January through March. Hood and 
Schlieder ( 1992), through histological examina- 
tion, showed that peak spawning occurred in 
