Giant Octopus

The octopus is a cephalopod of the order Octopoda that inhabits many diverse regions of the ocean, especially coral reefs. The term may also refer to only those creatures in the genus Octopus. In the larger sense, there are 289 different octopus species, which is over one-third the total number of cephalopod species.

The giant octopus ranges the coastal waters of Northern California through the Gulf of Alaska and around the Pacific Rim to Japan and Korea. Typically they are found in waters shallower than 100 fathoms ranging from the low intertidal zone to beyond 200 fathoms.

Octopuses are characterized by their eight arms, usually with sucker cups on them. These arms are a type of muscular hydrostat. Unlike most other cephalopods, the majority of octopuses — those in the suborder most commonly known, Incirrina — have almost entirely soft bodies with no internal skeleton. They have neither a protective outer shell like the nautilus, nor any vestige of an internal shell or bones, like cuttlefish or squids. A beak, similar in shape to a parrot's beak, is their only hard part. This enables them to squeeze through very narrow slits between underwater rocks, which is very helpful when they are fleeing from morays or other predating fish. The octopuses in the less familiar Cirrina suborder have two fins and an internal shell, making them a little less flexible in being able to squeeze into small spaces.

Three defensive mechanisms are typical of octopuses: ink sacs, camouflage, and autotomising limbs. Most octopuses can eject a thick blackish ink in a large cloud to aid in escaping from predators. They also have specialized skin cells both for color changing (chromatophores) and light reflection and refraction (iridophores and leucophores). They use this ability to blend into the environment to hide, as communication with other octopuses, or as a warning: the very poisonous Blue-ringed Octopus becomes bright yellow with blue rings when it is provoked. When under attack, some octopuses can autotomise their limbs, in a similar manner to skinks and other lizards. The crawling arm serves as a distraction to would-be predators; this ability is also used in mating. A few species have a fourth defense mechanism, in that they can combine their highly flexible bodies with their color changing ability to accurately mimic other, more dangerous animals such as lionfish and eels.

When octopuses reproduce, they use a specialized arm called a hectocotylus to insert spermatophores (packets of sperm) into the female's mantle cavity. The hectocotylus is usually the third right arm. In some species, the female octopus can keep the sperm alive inside her for weeks until her eggs are mature. After they have been fertilized, the female lays roughly 200,000 eggs (this figure dramatically varies between species). The female hangs these eggs in strings from the ceiling of her lair. After the eggs hatch, the young larval octopuses must spend a period of time drifting in clouds of plankton, where they feed on copepods, larval crabs and larval seastars until they are ready to sink down to the bottom of the ocean, where the cycle repeats itself (in some deeper dwelling species, the young don't go through this period). This is a dangerous time for the larval octopuses, however, as they become part of the plankton cloud and are therefore preyed upon by the many other plankton eaters.

Octopuses have a relatively short life span, and some species live for as little as six months. Larger species, such as the North Pacific Giant Octopus, may live for up to five years if they do not reproduce. However, reproduction is a cause of death: males can only live for a few months after mating, and females die shortly after their eggs hatch, for they spend nearly all their time caring for their eggs during the roughly one month period it takes the eggs to hatch, and do not eat during this period.

Octopus blood contains the copper-rich protein hemocyanin for transporting oxygen. Less efficient than the iron-rich hemoglobin of vertebrates, the hemocyanin is dissolved in the plasma instead of being bound in red blood cells and gives the blood a blue color.

Giant Squid

Giant squid are marine mollusks of the class Cephalopoda, represented by as many as eight species of the genus Architeuthis. They are deep-ocean dwellers that can grow to tremendous size: recent estimates put the maximum size at 10 m (33 ft) for males and 13 m (43 ft) for females from caudal fin to the tip of the two long tentacles. The mantle length, though, is only about 2 m (7 ft) in length (more for females, less for males), and the length of the squid excluding its tentacles is about 5 m (16 ft). However, there are reported claims of specimens of up to 20 m (66 ft), but none have been scientifically documented.

The first real evidence of the existence of a giant squid was in 1873 when one attacked a minister and a young boy in a dory in Bell Island, Newfoundland. A 17 m (55 ft) giant squid specimen washed ashore in Glover's Harbour, Newfoundland on November 2, 1878.

An underwater creature the length of a 6-storey building, with eyes the size of your head.giant sucking tentacles that cover eight arms, each longer than your car.huge parrot-like beaks designed to bite its unfortunate prey.

Despite their great length, giant squid are not particularly heavy when compared to their chief predator, the Sperm Whale, because the majority of their length is taken up by their eight arms and two tentacles. The weights of recovered specimens have been measured in hundreds, rather than thousands, of pounds. Though an adult has never been seen alive, post-larval juveniles have been discovered in surface waters off New Zealand, and there are plans to capture more such juveniles and maintain them in an aquarium in an attempt to learn more about the creature's biology and habits.

The reproductive cycle of the giant squid is still a great mystery, but what has been learned so far is both bizarre and fascinating; male giant squid are equipped with a prehensile spermataphore-depositing tube of over three feet (90 cm) in length, which extends from inside the animal's mantle and apparently is used to inject sperm-containing packets into the female squid's arms – how exactly the sperm then is transferred to the egg mass is a matter of much debate, but the recent recovery in Tasmania of a female specimen having a small subsidiary tendril attached to the base of each of its eight arms could be a vital clue in the solution of this enigma.

Giant squid possess the largest eyes of any living creature, over 30 cm (one foot) in diameter, and their arms are equipped with hundreds of suction cups in total; each is mounted on an individual "stalk" and equipped around its circumference with a ring of sharp teeth to aid the creature in capturing its prey by firmly attaching itself to it both by suction and perforation. The size of these suction cups can vary from 2 to 5 cm in diameter (one to two inches), and it is not uncommon to find their circular scars on the head area of sperm whales that have fed – or attempted to feed – upon giant squid. The only other known predator of the giant squid is the sleeper shark, found off Antarctica. Because sperm whales are skilled at locating giant squid, scientists have attempted to conduct in-depth observations of sperm whales in order to study squid.

One of the more unusual aspects of giant squid (as well as some other species of large squid) is their reliance upon the light weight of ammonia in relation to seawater to maintain neutral buoyancy in their natural environment, as they lack the gas-filled swim bladder that fish use for this function; instead, they use ammonia (in the form of ammonium chloride) in the fluid of their flesh throughout their bodies. This makes the giant squid unfit for human consumption, although sperm whales seem to be attracted by (or at least tolerant of) its taste.

Like all cephalopods they use special organs called statocysts to sense their orientation and motion in the water. The age of giant squids can be estimated by "growth rings" in the statocyst's "statolyth" much like counting tree rings. Much of what is known about these animals come from estimates based on these, and from beaks found in sperm whale stomachs.

The search for a live Architeuthis specimen includes attempts to find live young, including larvae. Larval Architeuthis closely resemble larvae of Nototodarus and Moroteuthis, with distinctive characteristics being the shape of the mantle attachment by the head, the tentacle suckers, and the beaks. Approximately 65 specimens, one-fifth of all the giant squid ever found, have been found in the waters off Newfoundland; the last in December 2004.

Recently, a possibly even more massive squid, the little known Colossal Squid Mesonychoteuthis hamiltoni, has been described in more detail due to a new specimen being found. It is an inhabitant of Antarctic waters, and unlike the giant squid, relies upon both claw-like hooks and suction cups on its arms and tentacles to capture prey. Although its body may be of greater size than the giant squid, its tentacles appear to be considerably shorter in length; it is also believed to be responsible for scars on the backs of sperm whales, through the use of hooks on its tentacles.

Giant Octopus / Giant Squid External Links

The Giant Octopus site
Devoted to the Giant Octopus in Alaska, where since 1995 I have been studying the ecology of this animal.

The St. Augustine Giant Octopus
Discovered a giant carcass on the beach that was partially buried in the sand, so it had probably already been beached for several days. They thought that it was a whale...

Giant Squid Encounters
The French dispatch steamer Alecton was cruising off the Canary Islands late in November of 1861 when its crew spotted something unusual in the water...

Giant Octopus: Enteroctopus dofleini
Some of the largest and smallest octopuses are found off the coasts of the United States.

Giant Octopus Images
Contains samples from our picture files on the Giant Octopus (Octopus dolfeini).

Giant Squid and Colossal Squid Fact Sheet
To ensure accuracy in reporting of these squid the following brief notes have been prepared....

The Legend of Armstrong, the Giant Octopus
Maybe you have some of these too: a favorite incident from your childhood that's one of your favorite memories. It tends to resurface at odd times, like right before you drift off to sleep, floating into view like a wad of dust that suddenly appears uninvited from under the couch.

In Search of Giant Squid
The giant squid lives in most of the world's oceans and is among the biggest animals in the sea . . .

Giant Squid by American Museum of Natural History
The American Museum of Natural History is one of the world's preeminent institutions for scientific research and education, with collections of more than 32 million specimens and artifacts.

The Giant Squid
There have been myriad accounts of sea goers and their encounters with creatures unknown to the world. There are reported attacks, harmless sightings, or mysterious carcasses washing ashore.

The Peculiar Mating Habits of Squid
Birds do it. Bees do it. Even educated fleas do it, the Cole Porter song goes. But there's nary a mention of the giant squid...

'Bizarre' giant squid spotted in deep seas
A bizarre creature with 20-foot-long spidery legs that lives in the cold, inky black three miles below the surface of the ocean has been discovered in photographs taken by deep sea submersibles.