198 
Fishery Bulletin 110(2) 
Table 2 
Prey found in stomachs of 375 lingcod ( Ophiodon elongatus) collected off Oregon, where n is the number of stomachs containing 
a particular prey type and ri is the total number of individuals of a particular prey type; %F 0 is the frequency of occurrence, and 
%N is the percentage of prey items. The preference rank for each of 14 aggregated prey categories is also provided, where l=most 
preferred prey and 14 = least preferred prey. 
Prey species 
n 
n 
%F 0 
%N 
Preference rank 
Transient and pelagic fishes 
Lampetra tridentata 
i 
i 
0.27 
0.31 
8 
Engraulis mordax 
2 
2 
0.53 
0.62 
6 
Clupea pallasii 
37 
109 
9.87 
33.64 
7 
Merluccius productus 
7 
8 
1.87 
2.47 
4 
Ammodytes hexapterus 
15 
49 
4 
15.12 
2 
Skates and flatfishes (soft bottom) 
3 
Raja spp. 
1 
1 
0.27 
0.31 
Hippoglossus stenolepis 
1 
1 
0.27 
0.31 
Citharichthys sordidus 
3 
3 
0.8 
0.93 
Parophrys vetulus 
1 
1 
0.27 
0.31 
Platichthys stellatus 
2 
2 
0.53 
0.62 
unidentified flatfishes 
5 
5 
1.33 
1.54 
Reef-dwelling fishes 
Rockfishes 
Sebastes melanops 
6 
6 
1.6 
1.85 
13,14 
Sebastes saxicola 
1 
1 
0.27 
0.31 
unidentified rockfishes 
Greenlings 
7 
9 
1.87 
2.78 
12 
Hexagrammos decagrammus 
3 
3 
0.8 
0.93 
11 
Ophiodon elongatus 
2 
2 
0.53 
0.62 
Unidentified fishes 
28 
33 
7.47 
10.19 
Sculpins 
Hemilepidotus hemilepidotus 
3 
3 
0.8 
0.93 
10 
Scorpaenichthys marmoratus 
2 
2 
0.53 
0.62 
Unidentified sculpins 
9 
9 
2.4 
2.78 
Invertebrates 
Octopus 
Octopus bimaculatus 
26 
30 
6.93 
9.26 
9 
Octopus dofleini 
5 
5 
1.33 
1.54 
Loligo opalescens 
3 
3 
0.8 
0.93 
5 
Pandalus spp. 
23 
27 
6.13 
8.33 
1 
Cancer magister 
2 
6 
0.53 
1.85 
The dominant prey type was Pacific herring (%F=9.87, 
%A = 33.64), a transient and pelagic species. Other prey 
types were clustered and far less dominant in the di- 
et (Fig. 4). Among sampling periods, empty stomachs 
ranged from 8-81% (mean 56% empty, n = 10 sampling 
periods, SE = 5.7). Among sampling months, May-Oc- 
tober, the presence of consumed prey among lingcod 
was unpredictable, regardless of the sampling month 
(ANOVA, F x 9 =1.77, P=0.22) and consumption of resi- 
dent prey appeared to be independent of consumption 
of transient prey (ANOVA, F 1 9 =2.46, jP=Q.15). 
There were 41 unidentified prey items, 33 of which 
were confirmed not to be rockfishes. Lingcod eat parts 
of animals they cannot swallow whole by tearing prey 
apart (e.g., Pacific giant octopus; personal observ.) and 
are thus not considered gape-limited with respect to 
prey preference. Larger lingcod consumed larger prey 
(Fig. 5) but not distinctly different prey types (adjusted 
coefficient of determination r 2 =0.29, one-way ANOVA 
F, 71 = 30.3, P < 0.01, n= 12 measurable prey items). Typi- 
cally, a single prey item (but as many as 17) was found 
in a stomach containing prey, and among those stom- 
achs containing more than one prey item, as many as 
four different species were found. 
Numerically, 52% of prey were transient and pe- 
lagic, 4% were associated with soft-bottom seafloors, 
44% were demersal reef-dwelling species, and of the 
latter, half were invertebrates. The importance of 
macroinvertebrates among local prey species is dif- 
ferent from what was found in previous studies. Sand 
