178 
Age, growth, and reproduction of Southern 
Kingfish (Menticirrhus americanus ): a 
multivariate comparison with life history 
patterns in other sciaenids 
Samuel D. Clardy 1 
Nancy J. Brown-Peterson 2 
Mark S. Peterson 2 
Robert T. Leaf 2 
Email address for contact author: samuel.clardy@usm.edu 
1 Marine Education Center 
Gulf Coast Research Laboratory 
University of Southern Mississippi 
703 East Beach Drive 
Ocean Springs, Mississippi 39564 
2 Department of Coastal Sciences 
College of Science and Technology 
University of Southern Mississippi 
703 East Beach Drive 
Ocean Springs, Mississippi 39564 
Abstract— Southern Kingfish (Men- 
ticirrhus americanus) is an abundant 
sciaenid in the northcentral Gulf of 
Mexico, but little is known of its life 
history. Our objectives were to describe 
demographic traits and compare the 
characteristics of this population with 
those of other recreationally and com- 
mercially important populations in the 
U.S. Exclusive Economic Zone (U.S. 
EEZ). We report significant differences 
in sex-specific weight at length. Otolith 
annulus formation occurred in April 
and May and maximum age was dr- 
years for both sexes. Length-at-age 
analysis indicated that mean asymp- 
totic total length (TL; TL^ ma i e =244 
mm, f ema i e =303 mm) and mean in- 
stantaneous growth rates (& ma i e = 1.12 
y _1 and &f e male=0-95 y -1 ) were signifi- 
cantly different between sexes. The 
mean length at 50% maturity (TL 50 ) 
for females was 171 mm TL, corre- 
sponding to an age at maturity of 1 
year. Gonadosomatic indices and his- 
tological examination of ovarian ma- 
turity phases indicated rapid gonadal 
development in February and March 
with females actively spawning from 
April to September. The interval be- 
tween spawning averaged 6.9 days, and 
the most frequent spawning occurred 
in June and July. Mean relative batch 
fecundity was 231.1 number of eggs 
g -1 of ovary-free body weight ^stan- 
dard error 35.7). Principal component 
analysis (PCA) of 5 variables from 17 
sciaenid populations in the U.S. EEZ 
identified 2 principal components that 
explained 68 . 1 % of variation among 
populations; these components rep- 
resent a size-related gradient and a 
gradient of spawning season dynamics. 
Five distinct groups were identified on 
the basis of fish size, age at maturity, 
spawning-season duration, and batch 
fecundity. 
Manuscript submitted 12 April 2013. 
Manuscript accepted 25 April 2014. 
Fish. Bull. 112:178-197 (2014). 
doi:10.7755/FB.112.2-3.6 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
The family Sciaenidae include many 
commercially and recreationally im- 
portant species and occur worldwide 
in temperate and subtropical marine, 
estuarine, and fresh waters (Chao, 
1995, 2002). There are 79 sciaenids 
that occur in North America (Page 
et ah, 2013); 36 of these species com- 
monly occur in waters of the U.S. 
Exclusive Economic Zone (U.S. EEZ), 
and 29 of those 36 species support 
either commercial or recreational 
fisheries or both (FishBase, http:// 
www.fishbase.org). However, only 11 
of these fishes are reported individu- 
ally in the NOAA National Marine 
Fisheries Service commercial (http:// 
www.st.nmfs.noaa.gov/commercial- 
fisheries/commercial-landings/annu- 
al-landings/index, accessed Septem- 
ber 2013) and recreational (http:// 
www.st.nmfs.noaa.gov/stl/recre- 
ational/queries/catch, accessed Sep- 
tember 2013) statistics databases. 
Despite the conspicuousness of this 
family, complete life-history infor- 
mation is not available for many of 
the commonly occurring species, in- 
cluding some economically important 
members. 
Understanding life-history strate- 
gies and the interaction among spe- 
cies traits, environmental factors, 
and population dynamics is not only 
important for fisheries management 
but also vital to predict population 
responses to a variety of natural and 
anthropogenic disturbances (Win- 
emiller and Rose, 1992; Winemiller, 
2005). A comparison of life-history 
traits of species within the single, di- 
verse family Sciaenidae can further 
the understanding of the dynamics 
of this valuable group of fishes. For 
example, analysis of the reproductive 
life-history traits of Sciaenidae in the 
Gulf of Mexico (GOM) and Caribbean 
Sea resulted in the recognition of 3 
major groups within this family that 
were defined by maximum length, 
fecundity, and duration of spawning 
season (Waggy et ah, 2006). Simil- 
iarly, Militelli et al. (2013) recently 
examined reproductive traits of 7 
sciaenids from the Buenos Aires, Ar- 
gentina, coastal zone and found that 
composite groups could be described 
on the basis of the length of the re- 
productive period and size of the 
spawning area. 
