Taylor and Gervasi: Feeding habits and dietary overlap of age-0 flounder 
175 
Table 2 (Continued) 
Winter flounder 
Summer flounder 
Prey taxon 
%F 
%N 
%v 
%IRI 
%F 
%N 
%V 
%IRI 
Worms 
Polychaeta (polychaete) 
Ampharetidae 
(ampharetid worm) 
1.9 (SE 0.04) 
0.3 (SE 0.01) 
0.6 (SE 0.01) 
0.2 (SE 0.01) 
0.1 (SE 0.01) 
<0.1 
<0.1 
<0.1 
Fabrida sabella (fan worm) 
8.6 (SE 0.2) 
2.8 (SE 0.1) 
1.9 (SE 0.1) 
1.6 (SE 0.1) 
0.2 (SE 0.04) 
<0.1 
<0.1 
<0.1 
Glyceridae (blood worm) 
0.1 (SE 0.01) 
<0.1 
<0.1 
<0.1 
- 
- 
- 
- 
Nereididae (clam worm) 
2.1 (SE 0.1) 
0.3 (SE 0.01) 
0.6 (SE 0.02) 
0.2 (SE 0.01) 
0.5 (SE 0.03) 
<0.1 
<0.1 
<0.1 
Phyllodocidae (paddle worm) 
8.0 (SE 0.2) 
0.9 (SE 0.02) 
1.2 (SE 0.03) 
0.6 (SE 0.01) 
- 
- 
- 
- 
Polydora spp. (mud worm) 
4.3 (SE 0.1) 
1.4 (SE 0.04) 
1.1 (SE 0.03) 
0.8 (SE 0.03) 
- 
- 
- 
- 
Unidentified polychaete 
26.6 (SE 0.4) 
4.8 (SE 0.1) 
8.1 (SE 0.1) 
5.8 (SE 0.1) 
3.9 (SE 0.1) 
0.7 (SE 0.02) 
1.0 (SE 0.03) 
0.4 (SE 0.02) 
Nematoda (nematode) 
2.1 (SE 0.1) 
0.2 (SE 0.01) 
<0.1 
<0.1 
0.1 (SE 0.01) 
<0.1 
<0.1 
<0.1 
Mollusks 
Bivalvia (bivalve) 
Mya arenaria (softshell) 
0.1 (SE 0.01) 
<0.1 
<0.1 
<0.1 
- 
- 
- 
- 
Unidentified clam 
(whole clam) 
1.1 (SE 0.03) 
0.1 (SE 0.01) 
0.2 (SE 0.01) 
<0.1 
- 
- 
- 
- 
Unidentified clam 
(clam siphon) 
25.2 (SE 0.4) 
6.9 (SE 0.1) 
5.4 (SE 0.1) 
4.8 (SE 0.1) 
1.4 (SE 0.1) 
0.2 (SE 0.01) 
0.1 (SE 0.01) 
<0.1 
Gastropoda 
0.2 (SE 0.01) 
<0.1 
<0.1 
<0.1 
- 
- 
- 
- 
Fish 
Anguilla rostrata 
(American eel) 
- 
- 
- 
- 
0.1 (SE 0.01) 
<0.1 
<0.1 
<0.1 
Catostomus commersoni 
(white sucker) 
- 
- 
- 
- 
0.4 (SE 0.03) 
0.2 (SE 0.02) 
0.4 (SE 0.03) 
0.2 (SE 0.02) 
Clupeidae (herring) 
- 
- 
- 
- 
1.0 (SE 0.04) 
0.3 (SE 0.01) 
0.7 (SE 0.03) 
0.4 (SE 0.02) 
Gobiidae (goby) 
- 
- 
- 
- 
0.1 (SE 0.01) 
<0.1 
<0.1 
<0.1 
Menidia menidia 
(Atlantic silverside) 
- 
- 
- 
- 
0.1 (SE 0.01) 
0.1 (SE 0.01) 
0.1 (SE 0.01) 
0.1 (SE 0.01) 
Micropterus salmoides 
(largemouth bass) 
- 
- 
- 
- 
0.1 (SE 0.01) 
<0.1 
<0.1 
<0.1 
Pseudopleuronectes americanus 
(winter flounder) 
- 
- 
- 
- 
2.4 (SE 0.1) 
0.3 (SE 0.01) 
1.1 (SE 0.04) 
0.4 (SE 0.02) 
Syngnathus fuscus 
(northern pipefish) 
- 
- 
- 
- 
0.3 (SE 0.01) 
<0.1 
<0.1 
<0.1 
Unidentified fish 
- 
- 
- 
- 
8.8 (SE 0.3) 
4.7 (SE 0.3) 
6.2 (SE 0.3) 
5.2 (SE 0.3) 
Detritus 
0.4 (SE 0.02) 
<0.1 
0.3 (SE 0.02) 
0.2 (SE 0.01) 
0.6 (SE 0.02) 
<0.1 
0.2 (SE 0.01) 
<0.1 
Total number of stomachs 
examined (nt) 
Percentage of empty stomachs (%) 
Total number of clusters (seine hauls 
with winter or summer flounder; nj 
Unique prey per stomach (mean) 
Niche breadth index (B) 
Dietary overlap index (a) 
1109 
10.2 
186 
3.0 (SE 0.04) 
0.24 
749 
4.7 
132 
2.1 (SE 0.03) 
0.30 
within the small-medium (40-59 mm TL) and me¬ 
dium-large (60-79 mm TL) size categories had 85.1% 
and 81.4% dietary similarities, respectively (SIMPROF: 
small-medium, 7t=2.42, P=0.10; medium-large, 71=2.21, 
P=0.20; Fig. 3A). Consumption of polychaetes remained 
consistent at these moderate body sizes i%IRI ~10- 
13%; unidentified, F. sabella, and Polydora spp.), but 
there was a decreased reliance on copepods {%IRI de¬ 
clined from 48.9% to 5.1%) and a greater importance 
of amphipods {%IRI increased from 34.3% to 63.7%) 
(Fig. 5A). There also was evidence of small-medium 
and medium-large winter flounder feeding on bivalves, 
and that feeding was mostly limited to siphon crop¬ 
ping {%IRI: 5.9% and 13.7% for small-medium and 
medium-large size categories, respectively) (Table 2). 
Large winter flounder (>80 mm TL) had 91.8% dietary 
similarity (SIMPROF: 7i=0.00, P=1.00; Fig. 3A). There 
was an absence of copepods in the diet of these winter 
flounder (%/P7=0.0%), and amphipods (%/P/=51.7%), 
polychaetes (%/P/=22.4%; unidentified and nereidids). 
