Fairchild et al.: Spring feeding of Anarhichas lupus on Stellwagen Bank, Massachusetts 
199 
Table 4 
Relative frequency of occurrence and weight, by species, of items found in the stomachs 
of 286 Atlantic wolffish ( Anarhichas lupus) from 23 May to 8 June 2011 on Stellwagen 
Bank National Marine Sanctuary, Massachusetts. 
Prey item 
Frequency (%) 
Weight (g) 
Sea scallop ( Placopecten magellanicus ) 
87.8 
25.4 
Hermit crab (Pagurus sp.) 
51.0 
1.8 
Ocean quahog ( Arctica islandica) 
46.6 
7.7 
Gastropods, unidentified to species 
46.3 
1.6 
Green sea urchin (Strongylocentrotus droebachiensis) 
43.9 
4.9 
Rocks 
34.5 
0.3 
Jonah crab ( Cancer borealis) 
25.3 
5.3 
Sand dollar ( Echinarachnius parma) 
2.7 
0.4 
Sea star, unidentified to species 
1.4 
<0.1 
American lobster ( Homarus americanus) 
1.4 
0.2 
Spider crab ( Libinia sp.) 
1.4 
<0.1 
Longhorn sculpin ( Myoxocephalus octodecemspinosus) 
0.7 
0.3 
Algae (green), unidentified to species 
0.7 
<0.1 
Common sun star ( Crossaster papposus) 
0.3 
<0.1 
Mussel, unidentified to species 
0.3 
<0.1 
Polychaete, unidentified 
0.3 
<0.1 
Tooth, Atlantic wolffish 
0.3 
<0.1 
Hook 
0.3 
<0.1 
preservation, was their reproductive status. Egg color 
is helpful for identifying stages of oocytes. Templeman 
(1986b) found that Atlantic wolffish eggs that had not 
developed beyond a “whitish condition” were indicative 
of mature females who had not spawned yet and that 
yellowish eggs were “newly-maturing” eggs. From gross 
visual inspection of the ovaries of these SBNMS fish, 
only a small proportion of females was spawning for 
the first time (3-4%, Fig. 4). The majority of females 
had yellow-orange oocytes, indicating that these fish 
likely were in prespawning condition (Fig. 4). Further 
studies with proper gonad preservation and histology 
would be helpful in differentiating these stages more 
accurately. 
Worth noting, Atlantic wolffish eggs were not pres- 
ent in any guts. After spawning, males remove eggs 
stuck to the exterior of the female’s body by sucking 
and spitting them out (Johannessen et al., 1993); it 
is reasonable to suspect that some eggs are ingested 
incidentally. In addition, in intensive culture, Atlantic 
wolffish have been observed eating eggs from other 
pairs, and females have been seen destroying their own 
unfertilized eggs (Johannessen et al., 1993). When At- 
lantic wolffish guts were excised from the fish in our 
study, they immediately were frozen on ice until analy- 
sis; we are confident that if eggs had been in the guts, 
they still would have been present during processing. 
The absence of wolffish eggs in the guts provides ad- 
ditional evidence that this population had not spawned 
in the recent past. 
In Atlantic wolffish, fecundity increases exponen- 
tially with increasing size (Gunnarsson et al., 2006; 
Templeman, 1986b; Falk-Petersen and Hansen 10 ), and 
because size is positively correlated to age, it is not 
surprising that older females generally had higher GSI 
than younger females (Fig. 3). In contrast, male Atlan- 
tic wolffish have relatively small testes and produce 
only a small amount of sperm, as would be expected for 
a species with internal fertilization; male GSI does not 
increase with age or TL. Even within the year, there is 
low variation in GSI for males >3 kg (6.6 lb) (Johan- 
nessen et al., 1993; Moksness and Pavlov, 1996; Pav- 
lov and Moksness, 1996), whereas females show pro- 
nounced GSI peaks leading up to spawning (Hansen, 
1992 as cited by Tveiten and Johnsen, 1999). 
Feeding ecology 
Often known for their unusual tooth structure, wolf- 
fishes have highly specialized teeth for capturing and 
grinding hard-bodied prey. Adults feed almost exclu- 
sively on hard-shelled benthic invertebrates. Past stud- 
ies in the GOM-GB region revealed that economically 
important bivalves (sea scallop, Iceland scallop [Chla- 
mys islandica ], ocean quahog [Arctica islandica], arks 
clam [Family Aricidea], and Atlantic surfclam [Spisula 
solidissima]) were the most predominant prey group in 
stomachs of Atlantic wolffish (13-108 cm TL) collected 
in spring (Nelson and Ross, 1992), followed by echino- 
10 Falk-Petersen, I.-B., and T. K. Hansen. 1991. Reproductive 
biology of wolffish Anarhichas lupus from north-Norwegian 
waters. ICES Council Meeting (C.M.) Documents 1991/G.14, 
17 p. 
