20 February 2014
In early January, off Japan’s Sadogashima Island, fisherman Shigenori
Goto made an extreme rare catch – a giant squid. Hauling in his net
from a depth of about 300 feet the fisherman was confronted by something
other than the fish he expected – a 12 foot squid weighing about 300
pounds. Now being studied at the Fisheries Ocean Research Institute in
Niigata Prefecture, the undersea giant lived only a few minutes after
being brought to the surface.
[image] Giant squid caught in net
Even this “giant” squid can barely compare to the record length of 40
feet and the record weight of nearly a ton. But even this incredible
size is nothing compared the legends that have been inspired by the
giant squid. Fishermen notoriously exaggerate the size of “the one that
got away” and, historically, seafarers did the same with the size and
nature of the giant squid.
[video] Giant Squid
There is a Norse legend of a tentacled sea monster called the
“kraken.” Bigger than the biggest giant squid, it was said to grow as a
large as an island and would gobble up whole ships. Encounters, not
with the “whole” giant squid, but sightings of its tentacles rising up
out of the water have resulted in countless legends of sea monsters.
Witnesses, seeing only the giant squid’s tentacles have imaginatively
described the unseen monster lurking below the surface.
[image] Sea Monster
Squid became a particular focus of study for naturalists from 1870 to
1880. During that decade, a large number of squid became stranded in
shallow waters near the shores of Newfoundland and New Zealand. Most
often, these squid died, and their remains washed up on a beach, more or
less intact. However, there was at least one reported attack of an
adult and a child in a small fishing boat off Bell Island,
Newfoundland. These years were the peak of what came to be called the
squid “strandings.” Though in smaller numbers, strandings have
continued to the present day.
[image] stranded squid
In the distant past, the washed-up remains of dead squid
were often thought to be sea monsters. The squid even came to share,
along with several other sea creatures, the nickname “devilfish.” In
fact, squid are pretty scary looking. I like to say squid have 10
arms. But, in fact, I’m mixing and adding the arms with, and to, the
tentacles. Technically, squid have eight “arms” and two “tentacles.”
But, whether arms or tentacles, both are lined with hundreds of
suckers — suction cups about 1 to 2 inches wide. Each of the suckers
is lined with a full set of “teeth” or serrated rings that pierce the
flesh and, together with the suction, attach the squid to its prey. The
suction cups run the length of the arms forming a circle around the
squid’s month, or rather, its beak, which strongly resembles that of a
parrot.
[image] Squid suckers
Like octopuses, squid use jet propulsion to move through the
water. They pull water into their body (mantle cavity) and push water
out in rhythmic pulses that propel the animal through the ocean. Their
“jet” accounts for most of the their movement, but gets a little help
from the squid’s small fins. Unlike most fish, which have a gas filled
swim bladder that regulates their depth in the water, the giant squid
maintains its depth through the presence of an ammonium chloride
solution throughout its body. Lighter than sea water, the solution
allows the squid to regulate its depth. And it has quite a range.
Although data is incomplete, giant squid seem to roam in a range of
depths between 1,000 to 3,000 feet. The comfort of the squid at such
darkness may be because of its eyes, which are the largest of any living
creature: 11 inches wide. Large eyes are more sensitive to light and
can detect even small changes in tone. Extremely light-sensitive vision
would serve the squid well in the darkness of these depths.as they feed on deep-sea fish and other squid species.
Giant squid are found throughout the world. They seem to prefer
moderate temperatures and are seldom found in either tropical or arctic
waters. Although fierce predators, themselves, giant squid often become
food for sperm whales. These giant whales are, possibly, the giant
squid’s only predator. Much of our knowledge of how the giant squid’s
suckers affect its prey come from scars left on sperm whales after their
struggle to make a meal out of a giant squid.
[image] Sperm whale skin scarred by squid
[video] The Giant Squids off Sea of Cortez
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