WENNER ET AL.: LIFE HISTORY OF BLACK SEA BASS 



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AGE 



Figure 8.— Percent female and transitional Centro- 

 pristis striata by size and age. 



Fall spawning probably extended into October 

 because many fishes obtained in November had 

 recently spent ovaries. 



Fecundity was significantly related to SL, TL, 

 weight, and age with the former three equations 

 having by far the highest r 2 values (Table 10). The 



Female • = Developing + Ripe 



Maturity  = Spent + Resting 

 Stage 



A M J J 



MONTHS 



Figure 9.— Maturity stages of female Centropristis striata by 

 month to illustrate bimodal spawning. 



least squares linear regression model of fecundity 

 on age explained only 33% of the variation in fecun- 

 dity. Observed mean fecundity and its standard 

 error increased with age (Table 11). The lowest 

 observed fecundity (17,000) was in a 2-yr-old fish (SL 

 = 108 mm; TL = 140 mm; weight = 45 g) and the 

 largest (1,050,000) was in a 438 mm SL fish (TL = 

 454; weight = 1,371 g) of undetermined age. 



Mortality 



Instantaneous rates of total mortality, as derived 

 from catch curves, for C. striata ranged from 0.721 



Table 10. — Least squares linear and geometric mean functional regression equations of fecundity (fee) on 

 total length (TL), standard length (SL), weight (WT), and age for Centropristis striata. Weight units are grams 

 and lengths are millimeters. All least squares regressions were significant at o = 0.01. 



Least squares equation 



GM functional equation 



log 10 fee = -0.605 + 2.335 (log 10 TL) 



log 10 fee = -0.309 + 2.318 (log 10 SL) 



log 10 fee = 3.057 + 0.822 (log 10 WT) 



log 10 fee = 4.529 + 0.913 (log 10 Age) 



Table 1 1 . — Observed mean fecundity at age and its 

 standard error (S^) for Centropristis striata, in the 

 South Atlantic Bight. 



to 1.430, and actual mortality rates were from 0.513 

 to 0.761. Values increased from 1978 to 1981. For 

 example, values of A rose from 51.3 to 73.3% for 

 trap-caught fish and from 51.6 to 76.1% for hook- 

 and-line caught fish older than age 4 (Table 12). Mor- 

 tality values of trap-caught and hook-and-line caught 

 C. striata were similar within years for each estima- 

 tion procedure. Mortality values, moreover were 

 similar between estimation procedures. We found 

 a significant correlation between the instantaneous 



735 



