228 
Fishery Bulletin 112(2-3) 
Table 3 
Observed means and ranges of body and somatic weights at age, measured in grams and years, respectively, of male and 
female Hickory Shad (Alosa mediocris) collected from the Roanoke River-Albemarle Sound watershed in 1996. Standard 
deviations (SD) are provided in parentheses. n=number of fish sampled. 
Age 
n 
Males 
Females 
Body 
weight 
Somatic weight 
Body weight 
Somatic weight 
Mean 
Range 
Mean 
Range 
n 
Mean 
Range 
Mean 
Range 
2 
16 
330 (41.7) 
273-411 
310 (35.8) 
256-388 
9 
391 (27.3) 
358-446 
343 (15.8) 
325-379 
3 
178 
319 (54.1) 
210-548 
300 (57.8) 
197-525 
78 
440 (85.4) 
291-839 
390 (71.1) 
280-612 
4 
69 
451 (70.2) 
316-698 
422 (59.8) 
297-640 
133 
591 (101.1) 
359-839 
505 (83.2) 
318-705 
5 
4 
452 (65.2) 
403-542 
430 (69.6) 
385-532 
18 
639 (113.9) 
447-908 
542 (84.6) 
417-710 
6 
1 
651 
638 
1 
1031 
871 
7 
2 
946 (192.0) 
810-1082 
779 (145.4) 
676-881 
Total 
268 
241 
and lengths for age-5 males were longer than observed 
values. Females were similar to males except for age- 
7 fish, which had back-calculated lengths that were 
shorter than observed values. Predicted FL values from 
the von Bertalanffy growth equation were less than the 
observed lengths for age-2 fish and greater than the 
observed lengths for fish of ages 5-7. Predicted lengths 
for age-3 and age-4 fish fell between the mean observed 
lengths for age-3 and age-4 males and females (Table 
2). Females were larger and heavier at age than males 
(Tables 2 and 3). 
Mortality, maturity, and fecundity 
Mortality estimates were lower for males than for fe- 
males. Total instantaneous mortality (Z) was 1.43 for 
males of ages 3-5, 1.76 for females of ages 4-6, and 
1.40 for both sexes combined. Annual total mortality 
(A) was 0.76 for males, 0.83 for females, and 0.75 for 
both sexes combined. Between 36% and 38% of both 
male and female Hickory Shad were sexually mature 
by age 2, most (>93%) were mature by age 3, and al- 
most all were mature by age 4 (Table 4). Virgin males 
represented 46.8% of the male population; an addition- 
al 45.5% had spawned once, and 7.7% had spawned at 
least 2 or more times (Table 4). No males exhibited 
more than 3 spawning marks. Virgin females composed 
only about one-fourth (24.9%) of the sample, 45.5% of 
females had spawned once before, and 29.1% of them 
showed evidence of spawning 2 or 3 times. One age-7 
female had 4 spawning marks (Table 4). 
Slowly increasing trends in the mean GSI were ob- 
served for Hickory Shad from both Albemarle Sound 
and Roanoke River through March, whereas mean GSI 
slowly decreased through the week of April 7-13 and 
then decreased quickly thereafter (Fig. 4). The mean 
number of ova per gram of ovarian tissue ranged from 
more than 1500 to less than 4000, and the anterior por- 
tions of both ovaries tended to have higher ova counts 
per gram of ovarian tissue than the posterior region. 
This relationship was significant for the left ovary 
(n=47, F=4.68, P=0.011) but not for the right ovary 
(F=1.21, P=0.303). The left ovary was significantly 
greater in weight and mean total egg counts than the 
right ovary (n = 186, £=3.686, P<0.001). Mean left ovary 
weight was 42.88 g, and mean right ovary weight was 
35.98 g. Mean left egg count was 111,037, and the right 
ovary contained an average of 93,630 ova. These means 
were not significantly different for the left and right 
ovaries (n=47, £=-1.746, P=0.840). Potential fecundity 
(PF) of female Hickory Shad generally increased with 
fish length, body weight, somatic weight, and age class 
(Table 5). Fecundity estimates ranged from 80,290 to 
478,944 ova (n=47). We used the following prediction 
equations: 
Log,, PF = 3.90(log e FL) 
- 10.46 (r 2 =0.63); 
(12) 
Log e PF = 1.33(log e BWT) 
+ 3.70 (r 2 =0.76); 
(13) 
Log e PF = 1.39(log e SWT ) 
+ 3.59 (r 2 =0.67); and 
(14) 
Log e PF = 0.30(Age) 
+ 10.97 (r 2 =0.52) 
(15) 
Feeding and mesentery fat 
Fish collected from the Roanoke River had significant- 
ly less mesentery fat reserves than Albemarle Sound 
fish (males: n=6 2, £=-3.050, P=0.005; females: n=110, 
£=-4.54, P<0.0001). Also, male fish from the Roanoke 
River had significantly less remaining fat than Roa- 
noke River females (n=98, £=-2.140, P=0.030), but this 
sex difference was not observed for fish collected in Al- 
