Stephen et al.: Comparison of life history parameters for landed and discarded fish off the southeastern United States 
299 
Table 4 
Percentage of mature fish by length interval for female vermilion snapper (Rhomboplites aurorubens ), red porgy ( Pagrus pagrus), 
and scamp ( Mycteroperca phenax ) by sublegal and legal classification. All fish were examined histologically. n=number of fish in 
samples. 
Vermilion snapper Red porgy Scamp 
Fork 
length 
(mm) 
Age 
range 
Sublegal 
size 
%{n) 
Legal 
size 
%(n) 
Age 
range 
Sublegal 
size 
%(n) 
Legal 
size 
%(n) 
Age 
range 
Sublegal 
size 
%(n ) 
Legal 
size 
%(n) 
101-120 
0-1 
0(3) 
— 
— 
— 
— 
— 
— 
— 
121-140 
0 
0(1) 
— 
— 
— 
— 
— 
— 
— 
141-160 
0 
0(3) 
— 
i 
0(1) 
— 
— 
— 
— 
161-180 
0-1 
0(3) 
— 
— 
— 
— 
— 
— 
— 
181-200 
0-1 
100 (1) 
— 
1-2 
0(2) 
— 
— 
— 
— 
201-220 
0-2 
47 (15) 
— 
0-1 
100(3) 
— 
— 
— 
— 
221-240 
1-6 
81 (43) 
— 
1-4 
63(11) 
— 
— 
— 
— 
241-260 
0-10 
97(153) 
— 
1-6 
89(55) 
— 
— 
— 
— 
261-280 
0-12 
100(171) 
100 (48) 
0-8 
97(147) 
— 
— 
— 
— 
281-300 
1-9 
— 
100 (69) 
0-12 
98 (193) 
— 
— 
— 
— 
301-320 
1-9 
— 
100 (68) 
0-11 
100(67) 
100(102) 
— 
0(1) 
— 
321-340 
1-9 
— 
100 (63) 
2-14 
— 
99 (131) 
2-4 
0 (1) 
— 
341-360 
2-10 
— 
100 (45) 
2-11 
— 
99 (103) 
3-5 
67(6) 
— 
361-380 
3-8 
— 
100(35) 
2-12 
— 
100(45) 
2-5 
83 (18) 
— 
381-400 
3-7 
— 
100(25) 
0-12 
— 
100(15) 
2-6 
88(26) 
— 
401-420 
3-9 
— 
100 (23) 
4-11 
— 
100 (9) 
2-7 
85 (59) 
— 
421-440 
3-8 
— 
100 (7) 
5-9 
— 
100 (7) 
2-8 
97 (135) 
— 
441-460 
4-7 
— 
100(7) 
5-9 
— 
100(4) 
3-7 
97 (143) 
— 
461-480 
5-7 
— 
100 (7) 
5-8 
— 
100(5) 
3-6 
96 (54) 
94(31) 
481-500 
— 
— 
— 
11 
— 
100 (1) 
3-17 
— 
100(46) 
501-520 
— 
— 
— 
— 
— 
— 
3-8 
— 
100 (40) 
521-540 
— 
— 
— 
— 
— 
— 
3-12 
— 
100(31) 
541-560 
— 
— 
— 
— 
— 
— 
4-12 
— 
100(25) 
561-580 
— 
— 
— 
— 
— 
— 
5-11 
— 
100 (21) 
581-600 
— 
— 
— 
— 
— 
— 
5-14 
— 
100 (22) 
601-620 
— 
— 
— 
— 
— 
— 
5-17 
— 
100(9) 
621-640 
— 
— 
— 
— 
— 
— 
7-13 
— 
100(11) 
641-660 
— 
— 
— 
— 
— 
— 
6-13 
— 
100 (10) 
661-680 
— 
— 
— 
— 
— 
— 
7-11 
— 
100 (8) 
681-700 
— 
— 
— 
— 
— 
— 
7-15 
— 
100(2) 
701-720 
— 
— 
— 
— 
— 
— 
10-12 
— 
100(2) 
721-740 
— 
— 
— 
— 
— 
— 
10-14 
— 
100 (2) 
study, showing a shift to older age at maturation. This 
may be a response to the reduced fishing mortality that 
was instituted to rebuild the stock. 
Age at transition was similar for both sublegal- and 
legal-size red porgy, indicating that different growth 
rates did not affect the age of sexual transition. In- 
stead, sexual transition may be related to other fac- 
tors, particularly local social dynamics. In fact, size 
at transition does not appear to have changed much 
over time. Although age at transition in our study (two 
years) was younger than previously reported values of 
3.5-5 years (Hood and Johnson, 2000; Daniels, 2003), 
mean size of transitional fish was similar (Daniels, 
2003; Harris, 2003). Using Allsop and West’s (2003) 
formulas to estimate age (2.5xage at maturity) and size 
at transition (80% of maximum body size), we found 
that the expected age at transition was similar to the 
observed value and the expected size at transition was 
within the range of the observed transitioning fish. 
Sex ratios at age in our study support these estimates, 
because by age 2 sex ratios are approximately 1:1.15, 
by ages 3 and 4 are close to 1:1, and by age 5 favor 
males. Similarly, sex ratios for red porgy smaller than 
320 mm FL favored females, between 320 and 359 mm 
FL were close to 1:1, and favored males after 360 mm 
FL. Primary males (juvenile transitional fish) are often 
a socially mediated plastic response to high population 
densities or sex ratios that severely favor females (Liu 
