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Fishery Bulletin 111(4) 
mysids (4.8-20.6%), rock crabs (2.7-23.8%), and large 
amounts of UID and other fishes (24.7-35.3%). About 
10% of medium Summer Flounder diet in July was 
composed of pelagic Round Herring ( Etrumeus teres), 
and small Summer Flounder consumed a substantial 
amount of Weakfish. Medium Weakfish formed their 
own group with a diet consisting largely of mysids 
(62.4%) and anchovies (Bay Anchovy and Anchoa spp.; 
17.1%), and decapod crustaceans were also present 
(5.1%). Small Bluefish also formed their own group, 
feeding principally on 2 prey types: anchovies (61.2%) 
and UID and other fish species (38.8%). 
Four groups were identified at 60% similarity by 
the cluster analysis in August, 2 with broad diets, 1 
intense piscivore, and 1 bivalve consumer. The first 
broad diet group included medium and large Sum- 
mer Flounder, which consumed varying amounts of 
UID fishes (29.7-41.0%), squids (3.5-28.0%), Round 
Herring (7.6-28.9%), mysids (0.7-19.7%), rock crabs 
(6.4-11.8%), and ocellate lady crab ( Ovalipes ocella- 
tus; 0. 1-6.2%). The second broad diet group, consist- 
ing of medium and small Weakfish and small Summer 
Flounder, also consumed large amounts of UID and 
other fishes (21.5-42.1%). However, this group differed 
from the previous group in the consumption of mysids 
(16.3-37.9%), shrimps (3. 2-8.0%), ocellate lady crab 
(0-7.9%), decapod crustaceans (0. 8-7.0%), anchovies 
(9.9-17.6%), Weakfish (0-23.5%), and Butterfish (0- 
8.4%). Although cannibalism by medium Weakfish was 
substantial (23.5%) during this month, Weakfish were 
not detected in the diets of small Weakfish or small 
Summer Flounder. Small Bluefish, with a diet of an- 
chovies (75.6%), Weakfish (9.5%), and UID and other 
fishes (12.3%), made up the piscivore group. Striped 
Bass, composing the fourth group in August, consumed 
mostly bivalves (45.3%) and some UID and other fish 
species were present (6.1%). 
In September, the cluster analysis identified 2 
groups at the 60% similarity level from the 4 species 
size classes with enough data. The first group, consist- 
ing of medium and small Weakfish and small Bluefish, 
consumed varying amounts of anchovies (29.3-35.4%), 
mysids (<1-34. 5%), and UID and other fish species 
(25.3-64.2%). Medium Summer Flounder made up the 
second group and differed from the previous group by 
displaying a more diverse diet that included rock crabs 
(13.7%), mysids (13.2%), Round Herring (12.8%), and 
nondecapod crustaceans (7.2%) in addition to anchovies 
(28.2%). 
In October, 4 groups were identified, along with UID 
and other fish species as the primary diet component 
for each of them. The first group, consisting of small 
and medium Weakfish and medium Summer Flounder, 
differed from the rest primarily in the amounts of prey 
consumed: anchovies (4.3-18.0%), mysids (2.8-23.2%), 
sand lances (0-13.3%), Weakfish (0-9.5%), UID and oth- 
er fishes (43.1-71.7%), decapod crustaceans (0.3-9. 4%), 
and squids (0-6.6%). The second group, composed of 
small and large Bluefish, preyed on a variety of fish 
species, including anchovies (15.5-33.9%), Atlantic 
Menhaden ( Brevoortia tyrannus; 1.3-7. 2%), Butterfish 
(2. 6-4.0%), Northern Puffer ( Sphoeroides maculatus\ 
0-6.7%), Weakfish (2.8-25.2%), UID and other fishes 
(35.3-46.8%), and squids (5.0-12.1%). Large Weakfish 
formed the third group and consumed primarily At- 
lantic Menhaden (20.7%), with large amounts of UID 
and other fishes (70.3%), and a lesser amount of squids 
(6.2%). Striped Bass, the final group, consumed ocellate 
lady crab (8.2%) and a variety of fish species: Atlan- 
tic Menhaden (10.1%), Bay Anchovy (16.0%), Northern 
Puffer (19.2%), Weakfish (6.9%), and UID and other 
fishes (29.0%). Cannibalism among Weakfish was not 
prevalent in this month, although all other species con- 
sumed Weakfish to some degree. 
When the data are aggregated across months, 1 mul- 
tispecies group, 1 single-species group, and 3 groups, 
each of a single-species and single-size, emerge. The 
multispecies group consisted of small and medium 
Weakfish and small and medium Summer Flounder, 
with large and small Bluefish composing the single 
species group. The multispecies group consumed an- 
chovies (4.8-16.2%), sand lances (0-16.8%), Weakfish 
(<0. 1-6.2%), butterfish (0-9.2%), UID and other fishes 
(22.6-45.0%), mysids (10.9-28.9%), rock crabs (0-8.3%), 
decapod crustaceans (1.0-6. 9%), and squids (0.2-5. 1%). 
Large and small Bluefish also consumed a variety 
of fishes — Atlantic Menhaden (0.9-6. 4%), anchovies 
(17.1-42.2%), Northern Puffer (0-6.0%), Weakfish 
(3.8-22.2%), UID and other fish species (33.3-41.7%) — 
and squids (4. 8-9.0%) but consumed less mysids, rock 
crabs, and decapod crustaceans than did the multispe- 
cies group. Large Summer Flounder, the third group, 
consumed a mix of squids (55.4%) and fishes, mostly 
Round Herring (10.9%) and UID and other fish spe- 
cies (16.5%). The fourth group, large Weakfish, preyed 
mainly upon Atlantic Menhaden (19.8%), UID and 
other fish species (69.2%), and squids (5.9%). Striped 
Bass formed the final group, with a diet of bivalves 
(21.8%) and fishes: Bay Anchovy (8.3%), Atlantic Men- 
haden (5.3%), Northern Puffer (10.0%), UID and other 
fish species (18.0%). 
Habitat and diet overlap indices 
Monthly overlap (a from Schooner’s index) in habitat 
and diet for each pair of predators (species size classes) 
indicated shared use of resources (a>0); however, a was 
below the biologically important level of 0.6 in most 
months (Fig. 6). Some groups had substantial overlap 
( >0.6) in habitat but not diet (e.g., large, medium, and 
small Summer Flounder). There also were instances 
of overlap ( >0.6) in diet but not habitat (e.g., small 
Weakfish versus medium Weakfish and small Sum- 
mer Flounder). There were no cases where substantial 
overlap ( >0.6) in both habitat and diet occurred at the 
same time. For many of the pairwise comparisons, over- 
laps in both habitat and diet increased severalfold dur- 
ing the fall in this 5-month study, from levels of ~0.2 in 
