PLANKTON OF THE GULF OF MAINE 
17 
Although copepods usually dominate, the other boreal animals just mentioned 
are so nearly universal in the Gulf in summer that the planktonic community is then 
surprisingly uniform qualitatively, with the list of prevalent species varying hardly 
at all from station to station over its inner parts, as is illustrated by the two fol- 
lowing tables of catches made north of the Cape Cod- Cape Sable line during the 
summers of 1913 and 1914, seasons that may serve as representative because the 
plankton of the upper water layers was of the same general type during the sum- 
mers of 1912, 1915, and 1916, as I have pointed out eleswhere (Bigelow, 1917 
and 1922). 
Occurrence of representative species in the Gulf of Maine, August, 1913 
Species 
Stations 
Per cent 
of 
stations 
for each 
species 
cO 
00 
o 
o 
CO 
o 
o 
00 
OO 
o 
o 
05 
co 
I 
o 
05 
o 
o 
cm 
05 
8 
CO 
05 
8 
05 
o 
o 
o 
05 
o 
o 
t''. 
05 
o 
o 
CO 
05 
o 
o 
05 
05 
o 
o 
o 
o 
© 
o 
o 
CM 
o 
o 
CO 
o 
o 
Th 
o 
o 
iO 
o 
© 
Calanus finmarchicus 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
100 
Pseudocalanus elongatus 
CO 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 

X 
80 
Metridia lucens . 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
80 
Anomalocera pattersODi 
x 
x 
x 
x 
x 
x 
x 
x 
x 
X 
x 
x 
x 
x 
x 
x 
80 
Euchseta norvegica 
X 
X 
X 
x 
X 
X 
X 
X 
X 
X 
X 
X 
X 
70 
Meganyctiphanes norvegica 
X 
X 
X 
x 
X 
X 
X 
X 
40 
Thysanoessa inermis 1 __. 
Euthemisto compressa 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
90 
Euthemisto bispinosa 
X 
X 
x 
x 
x 
x 
x 
x 
X 
50 
Hyperoche broyeri 
x 
x 
x 
X 
x 
x 
X 
40 
Limacina retroversa 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
80 
Tomopteris catharina 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
60 
Sagitta elegans 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
100 
Phialidium languidum 
X 
X 
X 
x 
X 
X 
x 
x 
X 
X 
X 
X 
X 
X 
80 
Pleurobrachia pileus 
x 
X 
x 
x 
x 
X 
x 
X 
X 
X 
50 
1 
1 Data for Th. inermis are not available for 1913; it can, however, be assumed to occur in at least 80 per cent of the cases, since 
it was taken at 14 of our 18 midsummer stations in 1914. 
Occurrence of representative species north of Georges and Browns Banks, July and August, 1914 
Species 
July 
August 
CO 
CM 
O 
Th 
£ 
o 
8 
CM 
© 
I~- 
CM 
CM 
o 
cm 
CM 
o 
05 
cm 
CM 
o 
o 
ss 
o 
»o 
Th 
CM 
o 
5 
<M 
© 
Th 
CM 
o 
oo 
Th 
CM 
o 
05 
Th 
CM 
o 
o 
8 
o 
CO 
3 
o 
Th 
tO 
CM 
o 
to 
to 
CM 
o 
CO 
oi 
o 
Calanus finmarchicus 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Pseudocalanus elongatus - 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Metridia lucens 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Anomalocera pattersoni 
x 
x 
x 
x 
x 
Euchseta norvegica 
X 
X 
X 
X 
X 
X 
X 
X 
x 
x 
Meganyctiphanes norvegica.. 
X 
X 
X 
X 
X 
X 
X 
X 
x 
X 
Thysanoessa inermis 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Thysanoessa longieaudata 
X 
X 
X 
X 
.... 
X 
X 
X 
X 
X 
X 
X 
X 
Euthemisto compressa 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Euthemisto bispinosa 
x 
x 
X 
x 
X 
x 
X 
X 
X 
x 
x 
X 
x 
Limacina retroversa 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Tomopteris catharina. 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Sagitta elegans 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Sagitta serratodentata 
X 
x 
X 
X 
X 
X 
X 
X 
X 
X 
X 
X 
Notwithstanding the qualitative uniformity of the animal plankton of the 
waters of the Gulf of Maine in summer, the actual aspect of the catches of the tow 
nets often differs markedly from station to station, according to the relative abundance 
of their several components and especially of the copepods. As a rule these (chiefly 
Calanus, Pseudocalanus, and Metridia, with Euchseta in the deepest layers of 
