PLANKTON OP THE GULF OF MAINE 
115 
with fragments of herring, having found this to be the case in dozens of specimens. 
Young mackerel, too, suffer from their attacks, and we owe to Smith and Harger 
(quoted by Verrill, 1882, p. 306) a graphic account of their pursuit of the latter among 
the wharves of Provincetown Harbor during the month of July. Particularly inter- 
esting is their activity at such times, the ferocity of the attack, and the deadly nature 
of the single bite. The cannibalistic habits of Illex have likewise been commented 
upon, its own young being a common article of diet. This squid, like so many of the 
pelagic fishes, is very erratic in its appearance, being here to-day in hordes and gone 
to-morrow, perhaps to reappear in a few days. 
Illex provides a valuable source of bait for the offshore fishermen. It has been 
estimated that at one time squid formed fully half the bait supply of the vessels 
resorting to the Grand Banks (Goode, 1884), and we have record of 30,000 to 40,000 
taken in one Newfoundland harbor in a single day. Probably Illex never occurs 
in the Gulf of Maine (which is the southern outpost of its regular range) in such 
abundance as this, but as long ago as 1897 the squid fishery of Massachusetts Bay 
alone (no doubt this and the preceding species combined) yielded over a thousand 
barrels of bait, and in 1902 the catch of squid in Massachusetts was upward of 
5,000,000 pounds. At one time or another large numbers are taken by various 
methods all along the coasts of the Gulf as well as on the offshore banks. So voraci- 
ous and active an animal, and one at the same time so numerous, must take a heavy 
toll of the young fish, not to mention the various planktonic animals. 
Illex is probably to be classed as an oceanic animal, for it occurs commonly on the 
Grand Banks far from land and is often plentiful on Georges Bank as well. Probably 
its vernal appearance and continued presence off the coasts of the gulf of Maine 
throughout the summer are to be explained as a feeding migration (certainly this 
has nothing to do with its spawning), while its disappearance from the coast in 
autumn is part of a general offshore movement. Mr. Clapp’s capture of several 
large specimens on Georges Bank (taken in otter trawl) during the last week of Novem- 
ber in 1911 harmonizes with this suggestion. The fact that a whale (species unknown) 
that stranded on the south shore of Cape Cod on January 29, 1869, contained in 
its stomach thousands of Illex beaks 56 belonging to squids of about 12 to 15 inches 
body length throws no light on this point, for it may have eaten them many miles 
away from where it came ashore. We have no other winter records for Illex from the 
Gulf of Maine. 
Nothing is known of the breeding habits of this squid; its eggs have never been 
found, nor have its newly hatched young been recorded. 57 However, it is safe to 
say that it does not spawn along the coast of the Gulf of Maine at any season, for 
all the adult squids examined by Verrill and all that I have seen have been sexually 
inactive. Neither did McMurrich find its young at any season in his tows at St. 
Andrews. Indeed, the smallest Gulf of Maine specimens of which we can learn are 
one of about 10 centimeters, reported by Capt. H. E. Calder near Campobello, at 
16 Some hundreds of these are preserved in the collection of the Museum of Comparative Zoology. Their identity has been 
established by Mr. Clapp by comparison with the beak dissected from an Illex from Georges Bank, which measured about 14 inches 
in length from the edge of the mantle to tip ol tail. , 
51 One with a mantle measuring only 33 millimeters in length is recorded by Pfeffer (1912). 
