Craddock et at: Food habits of Lagenorhynchus acutus off the coast of New England 
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from 17 stomachs; and 7) red hake (Urophycis chuss), 
103 individuals from 14 stomachs. 
Gulf of Maine, winter 
The 20 stomachs containing prey from L. acutus net- 
caught in winter in the Gulf of Maine provide our most 
complete data set for analysis (Table 3). These stomachs 
contained 1155 fishes of 17 species and 274 cephalopods 
of three species. Five species, three fishes and two ceph- 
alopods, silver hake (45.3%), spoonarm octopus (14.3%), 
haddock (15.3%), red hake (18.7%), and longfin inshore 
squid (1.1%) accounted for almost 95% of the mass of 
prey. We were unable to calculate the mass of hagfish; 
their toothplates (the only hard parts remaining in the 
stomachs) are not proportional to an individual’s size. 
In order of frequency of occurrence and numerical 
abundance 1) the demersal silver hake was found in 
90% of the stomachs and accounted for 71% of the 
fishes eaten; 2) the benthic spoonarm octopus were 
found in 65% of the stomachs and accounted for 77% 
of cephalopods; 3) the demersal haddock were found in 
35% of the stomachs and made up 8.9% of the fishes; 
4) the demersal red hake were found in 65% of the 
stomachs and accounted for 7.7% of the fishes; 5) the 
benthic scavenger hagfish were found in 50% of the 
stomachs and accounted for 7.5% of the fishes; and 
6) the pelagic longfin squid were found in 60% of the 
stomachs and accounted for 23% of the cephalopods. 
The four fish species constituted 96% of the fish prey 
eaten, and the two cephalopods made up nearly all of 
the cephalopods consumed. Fishes made up 81% of all 
prey, and cephalopods, the remainder (19%). Notable 
were the scarcity or absence in winter of pelagic fish 
species (e.g., herring, alewives, smelt, mackerel, and 
sand lance). 
Gulf of Maine, summer 
Only three stomachs were available from animals net- 
caught in the Gulf of Maine in summer. These three 
contained 150 fishes of six species and six squids of two 
species (Table 4). The most abundant prey were silver 
hake, Atlantic herring, and red hake, which numeri- 
cally accounted for 63%, 19%, and 8% of total prey, 
respectively. These three species made up 29%, 64%, 
and less than 1% of total mass, respectively. Silver 
hake was numerically the most abundant species in 
both winter and summer stomachs. The pelagic Atlantic 
herring, which was almost absent in winter, was the 
most important species present in summer. The benthic 
spoonarm octopus, which was very abundant in the 
winter stomachs, was absent in summer. 
Continental Slope south of Georges Bank 
A single L. acutus was obtained south of Georges Bank 
near Munsen Canyon, in 500 m of water. This dolphin 
was a 252-cm lactating female. Its stomach contained 
over 3900 fishes of seven species (Table 4). Except for 37 
silver hake and one white hake, this individual had been 
feeding on open-ocean pelagic fishes, of which 99% (3875) 
were Madeira lanternfish. Two other lanternfishes (the 
glacier lanternfish [Benthosema glaciate ] and the soft 
lanternfish [Diaphus mollis]), the white barracudina 
(Arctozenus risso), and the boa dragonfish (Stomias boa) 
were also present. This stomach contained 9.6 kg of 
prey, the largest amount of any L. acutus in this study; 
Madeira lanternfish made up 58% of the prey mass, and 
silver hake 41%. 
Strandings 
Stomachs of the stranded dolphins contained little iden- 
tifiable material (Table 1). No nontrace fish or cepha- 
lopods were present in any of these stomachs. About 
one-quarter of the otoliths (27%) were too digested to be 
identified or measured and therefore could not be used 
for further analysis. Of the identifiable otoliths, 87% 
were those of sand lance, all from one stomach (Table 
2). The presence of these fish in that stomach was the 
only evidence indicating recent feeding. 
Twenty-nine of the 34 strandings occurred in the 
winter. Stomachs of these dolphins contained eight 
fish species and three cephalopod species. Sand lance 
constituted 79% of all prey (both fishes and cephalo- 
pods) and made up 60% of the total mass. Silver hake 
and longfin squid made up 18% and 16% of the total 
mass, respectively. Five fish species present in the 
stomachs of stranded animals — cunner ( Tautogolabrus 
adspersus ), radiated shanny ( Ulvaria subbifui'cata), 
rainbow smelt, sand lance, and yellowtail flounder (Li- 
manda ferruginea) — were not found in the stomachs 
of our net-caught dolphins. Of the five stomachs from 
nonwinter strandings, four were empty and the fifth 
(in September) contained only one identifiable fish, a 
silver hake. 
Prey species 
In the Gulf of Maine, silver hake was by far the most 
important prey species in the stomachs that we exam- 
ined. A schooling, demersal fish, silver hake is found 
only along the Atlantic coast of North America, from 
Florida to Newfoundland, at a wide range of depths, 
from shallow waters to 900 m (Collette and Klein- 
MacPhee 2002; Iwamoto 2002). Previously, reports 
indicated the presence of silver hake in L. acutus diets 
but not as an important prey. Among the few otoliths 
found in stranded L. acutus stomachs, silver hake was 
the second most abundant prey species (Table 4). 
Silver hake is also an important prey for other ma- 
rine mammals in the Gulf of Maine. It was a primary 
prey for harbor porpoise (Phocoena phocoena) during 
summer in the Bay of Fundy (Recchia and Read, 1989) 
and in autumn near Jeffreys Ledge in the western Gulf 
of Maine (Gannon et al., 1998). It was also the predomi- 
nant prey for net-caught young of the year harbor seals 
( Phoca vitulina) taken in shallow waters in the western 
Gulf of Maine (Williams, 1999). 
