Clardy et al.: Life history of Menticirrhus americanus and other sciaenids 
179 
Life-history patterns of many of the Sciaenidae in 
the northcentral GOM are not well understood, and 
limited life-history information is available on the 
Menticirrhus complex, which includes Gulf Kingfish, 
(Menticirrhus littoralis), Northern Kingfish (M. saxa- 
tilis), and Southern Kingfish (M. americanus). These 
species are targeted by both recreational and commer- 
cial fishermen in Mississippi, and all of them current- 
ly are unregulated in the northcentral GOM. Results 
from analysis of NOAA harvest data for 2000-11 indi- 
cate a decline in annual landings of Southern Kingfish 
from 117,967 to 36,332 kg in Mississippi waters dur- 
ing this time period (http://www.st.nmfs.noaa.gov/stl/ 
recreational/queries/catch, accessed September 2013). 
This decline likely was affected by a number of factors, 
and it may be cause for concern for the sustainability 
of the population. 
Southern Kingfish is a widely distributed estuarine 
sciaenid with a range in coastal waters from southern 
New England to the southern tip of Florida, the GOM 
and Caribbean Sea, and as far south as Argentina 
(Armstrong and Muller 1 ; Chao, 2002; Haluch et ah, 
2011; Militelli et ah, 2013); it is the most commonly oc- 
curring Menticirrhus species in northcentral GOM wa- 
ters. Although most frequently encountered over sandy 
bottoms (Chao, 2002), this species has been found in 
deep channels between barrier islands generally over 
sand, in shallow muddy bottoms, in seagrasses, or on 
shell hash (Reid, 1954; Bearden, 1963; Crowe, 1984). 
Seasonal movements of Southern Kingfish appear to 
occur from shallow waters, where it occurs in early 
spring through late fall, to deeper waters during the 
winter (Hildebrand and Cable, 1934; Bearden, 1963; 
Lagarde 2 ; Fritzsche and Crowe 3 ; Crowe, 1984). 
Updated information on age, growth, and reproduc- 
tion of Southern Kingfish in the middle South Atlantic 
Bight (SAB) was published last year (McDowell and Ro- 
billard, 2013) and includes the first age estimates from 
otoliths and fecundity estimates. However, similar cur- 
rent information, including histological assessment, for 
Southern Kingfish in the GOM had not been completed 
until we concluded the study presented here. McDow- 
ell and Robillard (2013) reported that the spawning 
1 Armstrong, M. P., and R. G. Muller. 1996. A summary of 
biological information for southern kingfish (Menticirrhus 
americanus). Gulf kingfish (M. littoralis), and northern king- 
fish ( M . saxatilis) in Florida waters. Florida Marine Research 
Institute (FMRI) In-house Report IHR 1996-004, 25 p. 
[Available from http://research.myfwc.com/publications/pub- 
lication_info.asp?id=43619.] 
2 Lagarde, C. C. 1981. Environmental requirements of se- 
lected coastal finfish and shellfish of the Mississippi Sound 
and vicinity: Southern kingfish Menticirrhus americanus 
(Linnaeus), 5 p. [Available from Mississippi State Univ. 
Research Center, NSTL Station, Mississippi, 105 Mill St.; 
Starkville, MS 39759.] 
3 Fritzsche, R. A., and B. J. Crowe. 1981. Contributions of 
the life history of the southern kingfish, Menticirrhus ameri- 
canus (Linnaeus), in Mississippi, 84 p. BMR Project No. 
CO-ST-79-022. [Available from Mississippi Department of 
Marine Resources, 1141 Bayview Ave.; Biloxi, MS 39532.] 
season for this species in the SAB was March-August 
and that peak activity occurred in April. That find- 
ing is similar to previous results from studies in the 
GOM; for those studies gonads were examined macro- 
scopically and indicated that the spawning season in 
the GOM lasts from February or March to November 
(Irwin, 1970; Crowe, 1984; Harding and Chittenden, 
1987), with a peak in April (Fritzsche and Crowe 3 ). 
Size at sexual maturity appears similar between the 
GOM and the SAB; Harding and Chittenden (1987) re- 
ported on the basis of macroscopic assessment that fe- 
males in the northwestern GOM reach 100% maturity 
at an age of 12-14 months or a size of 250 mm total 
length (TL), and McDowell and Robillard (2013) sug- 
gested that females from the SAB reach 50% maturity 
at 1.1 years or 199 mm TL. 
Knowledge of the reproductive biology and somatic 
traits of fish populations is required to assess the re- 
siliency of populations to fishing (Nielsen and Johnson, 
1983; Fulford and Hendon, 2010). To address gaps in 
knowledge, we describe a variety of reproductive and 
somatic traits, namely annual spawning season, spawn- 
ing frequency, batch fecundity, and size at 50% maturi- 
ty, for Southern Kingfish within the northcentral GOM 
that were determined by histological analysis and with 
standard techniques. We also quantified length at age 
and weight at length from analyses of nonlinear rela- 
tionships. Finally, we compare these traits with traits 
of other recreationally and commercially important sci- 
aenid populations in the U.S. EEZ to assess differences 
and similarities in life-history patterns of members of 
this family. 
Materials and methods 
Southern Kingfish were sampled from several loca- 
tions in the Mississippi Sound off the coast of Missis- 
sippi from April 2008 to May 2009 (Fig. 1). We targeted 
with hook and line a minimum of 50 fish each month 
from February to October and 15 fish from November 
to January. Haphazardly collected samples from crab 
pots and otter trawls during spring and summer were 
also obtained. Fish were identified according to Chao 
(2002). Upon collection, fish were immediately placed 
on ice and processed in the laboratory within 24 h. 
Each fish was measured for TL and standard length 
(SL) in millimeters and weighed in grams. The left 
sagittal otoliths of these fish were removed, cleaned, 
and dried; sex was determined macroscopically when 
gonads were removed and weighed (0.1 g). Sex-specific 
gonadosomatic indices (GSIs) were calculated: 
GSI = ( GW/GFBW ) x 100, (1) 
where GW = gonad weight; and 
GFBW = gonad-free body weight of the fish (Gree- 
ley et ah, 1986). 
A small cross section from the middle of the right 
gonad was removed and fixed in 10% neutral buffered 
