Stephen et ai.: Comparison of life history parameters for landed and discarded fish off the southeastern United States 
295 
test. Sublegal and legal mean ages were compared using 
a one-way ANOVA. Proportions of sublegal and legal 
fish within each age class were compared by using a 
2x2 contingency table with a chi-square test statis- 
tic or Fisher’s test statistic when cell sizes were low. 
Mean lengths of sublegal and legal size fish within 
each age class where compared by using individual 
one-way ANOVAs. For comparison with other studies, 
total lengths were converted to fork lengths based on 
equations generated from the 30+ year collaborative 
fishery-independent reef fish survey program MAR- 
MAP (Marine Resources Monitoring, Assessment, and 
Prediction) (M. Reichert, unpubl. data) (Table 2). All 
statistical analyses were done in SAS, vers. 9.2 (SAS 
Institute Inc., Cary, NC). 
Reproduction 
Reproductive tissues were stored in 10% buffered sea- 
water formalin for 1-2 weeks, after which samples were 
transferred to 50% isopropanol for 1-2 weeks. Reproduc- 
tive tissues were then vacuum-infiltrated in a tissue 
processor, blocked in paraffin, and sectioned (7 pm) on a 
rotary microtome. Three sections from each sample were 
placed on a glass slide, stained with double-strength 
Gill’s hematoxylin, and counter-stained with eosin-Y 
(Schmidt et al., 1993). Each section was viewed under a 
compound microscope (40-400x magnification) to deter- 
mine sex and reproductive state by criteria modified 
from Harris et al. (2001). Correct assignment of repro- 
ductive stage was confirmed through length histograms 
by reproductive state (immature and mature), in which 
there was little overlap in the tails of the distribution 
(Wyanski et al., 2000). 
Sex ratios (male:female) were compared to 1:1 ratios 
by using the chi-square goodness-of-fit test. The chi- 
square test (large sample sizes) or Fisher’s exact test 
(small sample sizes) were used to compare sex ratios of 
legal and sublegal size fish. Probability of maturation 
and transitions at length and age were calculated with 
the maximum likelihood estimates, and the Wald’s chi- 
square test statistic was used to compare probability 
estimates between sublegal- and legal-size fish. 
Results 
Vermilion snapper 
A total of 1739 vermilion snapper were collected, of which 
845 were legal-size (>305 mm TL) and 894 sublegal-size 
fish. Of these, 1638 were successfully aged. Age ranges 
were similar between legal- (1-10 years) and sublegal- 
size (0-12 years) vermilion snapper, but the distributions 
were significantly different (Kolmogorov-Smirnov test 
statistic [Z)] = 0.29, P<0.001) (Fig. 2A). As expected, the 
younger age classes (0-3 years) were predominantly 
sublegal size fish, whereas the older ages were predomi- 
nately legal size. Mean age (3.5 yr) of sublegal-size fish 
was significantly different from the mean age (4.5 yr; 
TabSe 2 
The linear relationship (with coefficient of determination 
[r 2 ]) between total length (TL) and fork length (FL) for 
vermilion snapper ( Rhomboplites aurorubens), red porgy 
(Pagrus pagrus), and scamp (Mycteroperca phenax) based 
on lengths collected through the 30+ year fishery-inde- 
pendent reef fish MARMAP (Marine Resources Moni- 
toring, Assessment and Prediction) survey off the coast 
of the southeastern United States. n=number of fish in 
samples for each species. 
Species 
FL-TL relationship 
n 
r 2 
Vermilion 
PL = 0.8948TL+1.127 
13,249 
0.9964 
snapper 
Red porgy 
FL = 0.8700TL+0.290 
16,498 
0.9924 
Scamp 
FL = 0.8745TL+26.903 
2910 
0.9883 
P=196, P< 0.001, degrees of freedom [df] =1) of legal-size 
fish. Proportions within each age class were significantly 
different except for age four (^=2.779, P=0.096, d.f.=l), 
where sublegal-size fish represented 46% of the catch 
(Fig. 2A). Sublegal vermilion snapper consistently had 
significantly smaller sizes at age for all comparable 
(n > 3 per classification) age classes ( F values between 
7.0 and 509.7, P values between 0.0181 and <0.001, 
df=l; Fig. 3A). 
Sex and maturity status were assigned to 1708 ver- 
milion snapper. Vermilion snapper sex ratios (M:F) 
of sublegal-size fish favored males (1:0.81; ^ 2 = 9.2, 
P=0.002, df=l), whereas there was no difference from a 
1:1 ratio for legal-size vermilion snapper (1:0.92; ^ 2 =1.4, 
P= 0.237, df=l). Sex ratios were not statistically differ- 
ent between legal- and sublegal-size vermilion snappers 
(^ 2 =3.2, P=0.07, df=l). Sex ratios for legal and sublegal 
sizes were not statistically different within age classes, 
except for age three (legal-size fish=l:1.10, sublegal-size 
fish=l:0.55; * 2 = 8.9, P=0.002, df=l). 
Size at 50% maturity could not be determined for 
legal-size vermilion snapper because all legal-size fish 
were mature. In fact, all males in this study were ma- 
ture, across all lengths (111-470 mm FL) and ages 
(0-12 years). There were 31 (3.9%) immature female 
sublegal vermilion snapper in our sample ranging in 
age from 0 to 2 years (Table 3) and in size from 99 
mm to 257 mm FL (Table 4). Including all females, of 
legal and sublegal size, length at 50% maturity was 
estimated at 212 mm FL (95% confidence intervals 
[Cl] = 197-220 mm FL) and 100% maturity was reached 
by 258 mm FL. 
Red porgy 
A total of 2009 red porgy were collected, of which 1014 
were legal size (>356 mm TL) and 1005 were sublegal- 
size fish. Of these, 2010 fish were successfully aged. Age 
ranges were similar between legal-size (0-14 years) and 
sublegal-size (0-12 years) red porgy, but the distribu- 
