122
&IALCOLY R. ULARXE
growth during 6 weeks of the inshore period and thought that this
indicated that successive waves of young squid were entering inshore
waters throughout the season. They also found that the squids taken
on the Grand Banks were smaller and were eating more than those
taken inshore. Squires (1957), however, found a steady growth through
the season inshore and the modes in size-frequency distributions taken
concurrently were the same in various sampling regions. From Squires’
data (Fig. ll), it appears that the young squid entering the region in
May were probably spawned the previous summer and that three large
individuals, well outside the range of the majority, were probably
2 years old. In October and November, k s t the larger and then the
smaller squids move south into deeper water. Some of the males then
possess spermatophores and large testes and the larger females axe
nearing maturity. Although there are some minor differences between
the sexes, and the mature females are larger, there is no marked difference
in proportion as in I . coindeti (Adam, 1952). Some males with 8
mantle length of 22.0 cm and all males of more than 25.0 cm, have
the right or left arm hectocotylized. At a mantle length of 23.0 cm the
testis is very large and, over 24.0 cm, spermatophores are present in
the penis. Squires (1957) only saw two ripe females, both caught in
May and with mantle lengths of 25.0 and 28.0 cm. Mating, spawning
and hatching must take place somewhere to the south in deep water,
probably on the continental slope of the United States where occasional
adults are caught during winter (Frost and Thompson, 1932).
Squires (1957) found some evidence that the squids are moving
farther north in recent years than they were in the early 1930’8, but
he was unable to find any cycles of annual abundance. He found that
onshore winds caused the squids to “disappear” from the squidding
grounds almost immediately.
During the summer and autumn the squids at f i s t feed mainly on
euphausids probably Meganyctiphanes and Thysanoessa (Squires, 1957)
and then, as they become larger, on capelin, herring, and mackerel
(Verrill, 1882c; Squires, 1957).
Besides the cod and mackerel which must be important predators of
Illex on the Grand Banks (Verrill, 1882c), the Pilot whale feeds almost
exclusively on it during summer and autumn (Squires, 1957). It has
also been taken from stomachs of Delphinapterus leucas (Vladykov,
1946) and Orthugoniscus mola (Adam, 1939~).
Much of the work on this species was initiated because of its great
importance to the “ fall ” cod fishery of Newfoundland, for which it
provides the principal bait. Particularly before refrigeration, the
fishery was frequently very adversely affected by the small numbers of
.
&IALCOLY R. ULARXE
growth during 6 weeks of the inshore period and thought that this
indicated that successive waves of young squid were entering inshore
waters throughout the season. They also found that the squids taken
on the Grand Banks were smaller and were eating more than those
taken inshore. Squires (1957), however, found a steady growth through
the season inshore and the modes in size-frequency distributions taken
concurrently were the same in various sampling regions. From Squires’
data (Fig. ll), it appears that the young squid entering the region in
May were probably spawned the previous summer and that three large
individuals, well outside the range of the majority, were probably
2 years old. In October and November, k s t the larger and then the
smaller squids move south into deeper water. Some of the males then
possess spermatophores and large testes and the larger females axe
nearing maturity. Although there are some minor differences between
the sexes, and the mature females are larger, there is no marked difference
in proportion as in I . coindeti (Adam, 1952). Some males with 8
mantle length of 22.0 cm and all males of more than 25.0 cm, have
the right or left arm hectocotylized. At a mantle length of 23.0 cm the
testis is very large and, over 24.0 cm, spermatophores are present in
the penis. Squires (1957) only saw two ripe females, both caught in
May and with mantle lengths of 25.0 and 28.0 cm. Mating, spawning
and hatching must take place somewhere to the south in deep water,
probably on the continental slope of the United States where occasional
adults are caught during winter (Frost and Thompson, 1932).
Squires (1957) found some evidence that the squids are moving
farther north in recent years than they were in the early 1930’8, but
he was unable to find any cycles of annual abundance. He found that
onshore winds caused the squids to “disappear” from the squidding
grounds almost immediately.
During the summer and autumn the squids at f i s t feed mainly on
euphausids probably Meganyctiphanes and Thysanoessa (Squires, 1957)
and then, as they become larger, on capelin, herring, and mackerel
(Verrill, 1882c; Squires, 1957).
Besides the cod and mackerel which must be important predators of
Illex on the Grand Banks (Verrill, 1882c), the Pilot whale feeds almost
exclusively on it during summer and autumn (Squires, 1957). It has
also been taken from stomachs of Delphinapterus leucas (Vladykov,
1946) and Orthugoniscus mola (Adam, 1939~).
Much of the work on this species was initiated because of its great
importance to the “ fall ” cod fishery of Newfoundland, for which it
provides the principal bait. Particularly before refrigeration, the
fishery was frequently very adversely affected by the small numbers of
.