FISHERY BULLETIN: VOL. 82, NO. 1 



100 125 150 175 200 



STANDARD LENGTH(mm) 



FIGURE 6. — Relationship of fecundity to standard length for banded 

 drum collected in North Carolina from April through September 

 1976. 



relationship was expressed by 



F = 15,490 + 28,024 (OW), r = 0.94, n = 85 



and had a much higher correlation coefficient than 

 either the length or body weight regressions. To 

 minimize monthly variation (Morse 1980) the most 



accurate prediction of fecundity was derived from 

 ovary weights only from the peak spawning month, 

 August, expressed by 



F = 18,532 + 28,181 (OW), r = 0.97, n = 31 



(Fig. 7). 



Sex Ratios 



Sex was determined for 2,729 banded drum and the 

 overall ratio of males to females varied significantly 

 from 1:1 in favor of females (Table 4). This non- 

 homogeneity of total sex ratios could not be account- 

 ed for by any consistent pattern of seasonal ratio 

 differences. The two largest size groups exhibited sex 

 ratios significantly in favor of females. The disparity 

 between sexes in the size range 100-139 mm SL was 

 accounted for during winter, spring, and summer, 

 while that in the fish > 140 mm SL was accounted for 

 during fall and winter (Table 4). Contingency table 

 analysis indicated strong dependency between sex 

 and size group (x 2 = 17.84, df — 3,P < 0.001), even 

 though differences in the smallest two size groups 

 were nonsignificant (Table 4). As fish grew, the 

 population shifted from more males to more females. 

 There were more total females than males in all 

 seasons except summer; however, the differences 

 were only significant in the fall. The fall divergence 

 from a 1:1 ratio was explained by differences in the 

 60-99 mm and >140 mm SL size groups (Table 4). 



F = 18,532+ 28,181I0WI 

 r =0.97 

 n = 31 



-i 1 1 1 1 I r- 



2 3 4 5 6 7 8 



OVARY WEIGHT (g) 



10 



11 



FIGURE 7. — Relationship of fecundity to overy weight during August 1976 for North Car- 

 olina banded drum. 



232 



