Wilson and Nieland: Reproductive biology of Saaenops ocellatus 



845 



26 September 1988. Numbers of hydrated oocytes 

 per gram of ovarian tissue were calculated for each 

 sample (n=72). Nested ANOVAshowed significant 

 variation only among individuals; no location ef- 

 fects were demonstrated (Table 3). All individual 

 batch fecundities herein are means of estimates 

 made from three different randomly selected re- 

 gions as defined above. 



Batch fecundity estimates were generated for a 

 combined sample of 51 red drum captured by purse 

 seine during the 1986 (previously reported by 

 Fitzhugh et al. (1988)), 1987, 1988, 1989, and 1991 

 spawning seasons. All displayed overt macroscopic 

 and microscopic manifestations of oocyte hydra- 

 tion throughout the length and diameter of the 

 ovarian lobes and were captured during the late 

 afternoon or early evening hours (1600-1900 h). 

 No sufficiently hydrated females were encountered 

 in 1990 and 1992. 



Age, FL, batch fecundity ranges, and numbers 

 of hydrated specimens examined by year of cap- 

 ture are given in Table 4. Regression analyses of 

 batch fecundity against FL (r 2 =0.58), gonad-free 

 body weight (r 2 =0.46), age in year (r 2 =0.43), and 

 BW (r 2 =0.43) are of reasonable predictive value 

 (Fig. 3). Significant positive relations (P>0.0001) 

 were indicated between batch fecundity and 

 nontransformed values of the four independent 

 variables. The relatively low r 2 values for the re- 

 gressions appear to result from individual varia- 



MJSDMJSDMJSDMJSDM 



1986 | 1987 | 1988 | 1989 | 



Month/Year 



Figure 2 



Monthly mean percent occurrence of primary growth (dia- 

 monds), cortical alveoli (crosses), and vitellogenic (squares) 

 oocytes in ovaries of red drum from the northern Gulf of 

 Mexico. Total sample size is 1,379; for months during which 

 female red drum were available, sample size ranged from 

 1 to 160. Dashed lines span months during which speci- 

 mens were unavailable. Ranges of standard deviations 

 (SD) during August-October were 3.4-18.3 for primary 

 growth oocytes, 0.0-3.4 for cortical alveoli oocytes, and 2.2- 

 13.1 for vitellogenic oocytes. 



Table 2 

 Percent maturity and numbers sampled (in parentheses) of female and male red drum at age, fork length, and total 

 weight. Specimens included are those taken by all gears during August through October of 1986-1991 and August 

 and September 1992. Total sample sizes are 1,262 females and 1,137 males. 



