162 
Fishery Bulletin 115(2) 
Estimated age (years) 
Figure 5 
Age-frequency distributions for sheepshead {Archosargus probatocephalus) 
collected in Tampa Bay, Florida, 1993-2009. 
Estimated age (years) 
Figure 6 
Observed fork lengths and estimated ages of female (indicated by black 
circles) and male (indicated by open triangles) sheepshead (Archosargus 
probatocephalus) collected in Tampa Bay, Florida, 1993-2009. The lines de¬ 
pict the predicted size at age from the von Bertalanffy growth models for 
males and females. Von Bertalanffy growth parameters for both sexes are 
presented in Table 3. 
Growth 
Results of growth studies of sheeps¬ 
head have shown marked geographic 
variation. Sheepshead in northern 
areas of the Gulf of Mexico and 
Atlantic are longer lived and grow 
larger than those in Florida (Beck¬ 
man et al., 1991; Wenner^; Dutka- 
Gianelli and Murie, 2001). We found 
that the growth of sheepshead in 
Tampa Bay was similar to that re¬ 
ported farther north along the gulf 
coast of Florida. Sheepshead from 
Tampa Bay were observed to reach 
at least 524 mm FL and to reach an 
estimated maximum age of 15 years. 
Dutka-Gianelli and Murie (2001) 
collected sheepshead in northwest 
Florida with a similar maximum age 
(15 years) and size (522 mm FL). In 
contrast, sheepshead from Louisiana 
(Beckman et al., 1991) lived longer 
(20 years) and grew larger (563 mm 
FL) than sheepshead collected in 
Florida (Dutka-Gianelli and Murie, 
2001; our study). Specimens col¬ 
lected in South Carolina (Wenner^) 
included the greatest reported esti¬ 
mated age for sheepshead (26 years). 
Wenner^ also reported a sheepshead 
maximum size (560 mm FL) similar 
to that reported for sheepshead from 
Louisiana. 
Fish length is a poor measure 
for estimating age in sheepshead. 
Sheepshead of similar age can dif¬ 
fer considerably in length (Schwartz, 
1990; Beckman et al., 1991; Wenner^; 
Dutka-Gianelli and Murie, 2001; our 
study). For example, in our study, 
age-5 sheephead ranged from 212 to 
465 mm FL, and 350-mm-FL speci¬ 
mens ranged from age 2 to age 8. 
Length has also been seen as unreli¬ 
able for estimating the age for other 
sparids, including red porgy {Pagrus 
pagrus; Hood and Johnson, 2000), 
black bream (Acanthopagrus butch- 
eri; Sarre and Potter, 2000), pinfish 
(Lagodon rhomboides; Nelson, 2002), 
and littlehead porgy (Calamus pro- 
ridens' Tyler-Jedlund and Torres, 
2015). 
Although growth models for male 
and female sheepshead from Tampa 
Bay differed statistically, the actual 
growth parameters were biologically 
very similar for the sexes. Sex-specif¬ 
ic growth models had a significantly 
