Willis et al.: Feeding behavior of 3 sciaemds along the southeastern United States 
291 
1884; Chao, 2002). In the southeastern United States, 
these species have a similar life history; they grow rap- 
idly and are capable of spawning as early as 1 year of 
age (Walton, 1996). 
Weakfish generally spawn from March through July 
in estuarine and nearshore waters, and juveniles use 
the estuary as nursery grounds. From 2008 through 
2010, weakfish with an average age <1 year old and 
a mean of 21 cm in total length (TL) were captured in 
SEAMAP-SA trawl surveys, but this species reportedly 
lives to 8 years and can reach a length of 90 cm TL 
(Shepherd and Grimes, 1983; Chao, 2002). Adult weak- 
fish migrate seasonally between nearshore and offshore 
waters, and forage throughout the water column. 
Southern kingfish are bottom foragers that spawn 
on the continental shelf from April through August, 
live up to 6 years, and can grow to lengths of 60 cm 
TL (Bearden, 1963; Smith and Wenner, 1985; Chao, 
2002). For southern kingfish captured by SEAMAP-SA 
from 2008 to 2010, the average age was 1 year and 
the average size was 18 cm TL. Atlantic croaker are 
shelf-spawners during October-January and can reach 
an age of 15 years and length of 46 cm TL (Hales 
and Reitz, 1992; Barbieri et al., 1994; Richardson 
and Boylan 2 ). From 2008 to 2010, the mean age and 
length for specimens of Atlantic croaker collected by 
SEAMAP-SA were 1 year and 22 cm TL, respectively. 
Atlantic croaker are demersal and use their inferior- 
located mouth to suck prey from the substrate (Over- 
street and Heard, 1978). Juveniles of both southern 
kingfish and Atlantic croaker use estuaries as nurser- 
ies, a characteristic similar to weakfish (Musick and 
Wiley, 1972; Harding and Chittenden, 1987). 
Although the life history of these 3 species has been 
studied extensively, quantitative diet information from 
the southeastern United States is either lacking or was 
collected 2 or more decades ago. The potential for diet 
overlap among sciaenids with similar feeding strate- 
gies has not been addressed in this region to date. Mer- 
riner (1975) examined the diet of weakfish captured in 
North Carolina waters and found that penaeid and 
mysid shrimps, anchovies, and clupeid fishes were the 
most common food items. He noted a gradual onto- 
genetic shift from shrimp to clupeids, specifically the 
Atlantic thread herring (Opisthonema oglinum), begin- 
ning when weakfish were about 19 cm standard length 
(SL) and 1 year of age. McMichael and Ross (1987) 
analyzed the diets of southern kingfish, northern king- 
fish ( Menticirrhus saxatilis), and gulf kingfish ( M . lit- 
toralis) in the Gulf of Mexico and found that southern 
kingfish most frequently consume bivalve siphons and 
cumaceans, followed by mysids, polychaetes, brachy- 
urans, and gammarid amphipods. Although frequency 
2 Richardson, J., and J. Boylan. 2013. Results of trawling 
efforts in the coastal habitat of the South Atlantic Bight, 
2012. Report SEAMAP-SA-CS-2012-004, 101 p. [Available 
from Mar. Resour. Res. Inst., Mar. Resour. Div., South Caro- 
lina Dep. Natl. Resour. 217 Fort Johnson Rd., Charleston, SC 
29422.] 
of prey items seemed to be dependent on season, prey 
item composition was not found to be significantly dif- 
ferent among species within a season in that study. A 
diet study of species of Menticirrhus, conducted near 
the Patos Lagoon in Brazil, has shown both low species 
diversity and seasonal differences in prey consumption, 
with polychaetes, amphipods, and various crustaceans 
being consumed most frequently (Rodrigues and Vieira, 
2010). Overstreet and Heard (1978) studied Atlantic 
croaker diets in the Gulf of Mexico and found a high 
diversity of prey items, including polychaetes, mysids, 
blue crabs, amphipods, and penaeids, among other prey 
items. 
Each of these fish species is important both commer- 
cially and recreationally, and each commonly occurs as 
bycatch in the shrimp trawl fishery (Smith and Wenner, 
1985; Murray et al., 1992; Diamond et al., 2000). In ad- 
dition, Atlantic croaker is harvested for use in the bait 
industry (Ross, 1988). Management of these species has 
become necessary as these industries evolve and catch 
levels increase. 
We investigated the diets of weakfish, southern king- 
fish, and Atlantic croaker off the southeastern United 
States to provide current regional information on their 
diets. We also assessed the overlap in prey among the 
3 species and examined several factors that may influ- 
ence this assessment, including spatial and temporal 
variation in sampling. 
Materials and methods 
Field sampling 
Fishes were collected from 2008 to 2010 during 
shallow-water trawl hauls conducted as part of the 
SEAMAP-SA Coastal Survey by staff of the South Car- 
olina Department of Natural Resources. Paired 22.9- 
m mongoose-type Falcon 3 trawl nets (Beaufort Marine 
Supply, Beaufort, SC), which had a net body of no. 15 
twine with 4.8-cm stretch mesh and a cod end of no. 
30 twine with 4.1-cm stretch mesh, were deployed from 
the RV Lady Lisa, a 23-m wooden-hulled, double-rigged 
St. Augustine Trawlers (St. Augustine Trawlers Inc., 
St. Augustine, FL) shrimp trawler. Trawl hauls were 
conducted during daylight hours at target speeds of 1.3 
m/s (2.5 kn) for 20 min and at depths between 4 and 
10 m (Hendrix and Boylan 4 ). For the Coastal Survey, 
trawl hauls are conducted at randomly selected loca- 
tions within 6 regions from Cape Canaveral, Florida, 
to Cape Hatteras, North Carolina (Fig. 1). Regions are 
3 Mention of trade names or commercial companies is for iden- 
tification purposes only and does not imply endorsement by 
the National Marine Fisheries Service, NOAA. 
4 Hendrix, C., and J. Boylan. 2011. Results of trawling 
efforts in the coastal habitat of the South Atlantic Bight, 
2010. Report SEAMAP-SA-CS-2010-004, 108 p. [Available 
from Mar. Resour. Res. Inst., Mar. Resour. Div., South Caro- 
lina Dep. Nat. Resour, 217 Fort Johnson Rd., Charleston, SC 
29422.] 
