In 2012, The Discovery Channel was able to catch a live
Giant Squid on an undersea camera. While
most research is done off New Zealand, this footage was captured off Japan. Giant Squids were first recorded live in 2006,
after researchers suspended bait beneath a research vessel off the Ogasawara
Islands (Japan) to try and hook a giant squid. While filming, the research team
from Japan's National Science Museum pulled a 24-foot (7-meter) squid to the
surface. The more recent footage is from
the same area, and was captured deep within the squid’s natural habitat, a
first for researchers
.
The longest Giant Squid mantle length on record is 7.4 feet
(2.25 meters) and the length from the tip of the top fin to the end of the arms
seldom is more than 16 feet (5 meters).
The longest total length (including tentacles) of a squid on record is
43 feet (13 meters). This is far smaller
than the 20 meter length rumored. One of
the explanations of this is that when the squids die and wash ashore, they are
often quite bloated and worn from other species attacking them or feeding on
them. Exaggerations arise from sightings
of life ones as well, as running across one of these monsters in open sea can
be a frightening experience. The eye of
this squid can be as large as a beach ball.
Some researchers think there are as many as 8 species in the
genus Architeuthis, each a different kind of giant squid. Other researchers
think there is just one Architeuthis species, or Giant Squid. Few specimens are available for study. However,
there are an estimated 500 species of squid overall, some only about an inch
long and others (The Colossal Squid, Mesonychoteuthis hamiltoni), which can
grow to 45 feet (14 meters).
An international team headed by Danish researchers tested
DNA samples from 43 giant squid from around the world and were stunned to find
that there is likely just a single species of the massive cephalopod. The genetic diversity among the samples was
lower than in almost any species ever reported, said Tom Gilbert, a researcher
from the Natural History Museum of Denmark at the University of Copenhagen.
“That lack of diversity and no population structure is just
crazy. We just cannot explain it easily once you start thinking that this is an
animal that lives everywhere,” Gilbert said in an interview.
Giant Squids are closely related to snails, clams, and even
slugs. Cephalopods have been around for
500 million years. Cephalopods are
defined not by whether they have a shell, but by their soft bodies. Squids and cuttlefishes also have a backbone-like
support made of chitin. They have well
developed brains and many can change skin color or texture. They also use ink as a defense. It is also believed that they may have come
close to being extinct at one point.
There appears to be only one species of Giant Squid. Given the vast distribution of them, more
genetic mutations and cross breeding would be expected. The findings are published in the journal
Proceedings of the Royal Society. Researchers
from the University of Copenhagen and researchers from Australia, Japan,
France, Ireland and Portugal took 43 tissue samples from a variety of sources,
including stranded animals, remains found in the stomachs of beached sperm
whales and accidental by-catch. They then used DNA sequencing techniques to
understand the genetic makeup of the squid. Genetic diversity was also found to
be very low, meaning that the squid are genetically very similar despite being
found all over the world and varying greatly in appearance.
"There's normally local distinction between [animals]
genetically," Professor Thomas Gilbert told BBC Nature. "Things that live in one area eventually
become different from things in other areas but [giant squid] are basically
identical everywhere." He suggested
that migration could be the key reason specimens from as far apart as Japan and
Florida, US are so genetically similar.
"We speculate the larval stage must drift globally in
the currents then dive to the nearest dark, deep spot when they are large
enough, thus stopping any [population] structure appearing," he explained.
"Instead of the adults and their young living in the same place, the young
distribute to a completely new place on the Earth every time."
Another theory to explain the large numbers of identical
animals is the possibility of a rapid, recent population boom. The Giant Squid are remarkably able to adjust
to their environment. This, their diverse
locations they are found, and their significant size lead scientists to believe
the giant squid have a substantial population rather than being as rare as once
believed.
The giant squid has been a source of fascination both before
and beyond its formal description in 1857 by Danish biologist Japetus
Steenstrup.
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