Press "Enter" to skip to content

Blue Bloods of the Sea

Octopus blood is actually blue, essentially because it has a copper-based protein called hemocyain. That blueblood is pumped through the octopus by three hearts. The central heart pumps the blood through the body to provide oxygen to the organs, while the two peripheral hearts pump blood through the gills, where it picks up oxygen. Oddly, when an octopus is swimming the heart that delivers blood to the organs stops beating which makes the octopus tired. That is why an octopus would rather crawl along the ocean floor than swim.
The octopus is a marine mollusk and a member of the class Cephalopoda, more commonly called cephalopods. Cephalopoda means, “head foot” in Greek, and in this class of organisms, the head and feet are merged. There is a ring of eight long arms that are equal in length. They use their arms to “walk” on seafloor. The undersides of the arms are covered with suction cups that are very sensitive to touch and taste. Their bodies are sack-like with a head position at the top. In the head there are two eyes, which are very complex and sensitive. On the underside tucked up in the center of the arms, there is beak or mouth that is capable of penetrating a hard shell.
One of the more fascinating things about octopus is that they range in size from very small to gigantic. Some experts believe their brains are as complex as many vertebrates. Giant octopuses have been found to weigh 600 pounds with a 30-foot arm span. They are reputed to be incredibly smart and have actually been observed to solve mazes and to mimic the behavior of other species of octopus. They also have an appetite for shrimps, lobsters, birds and possibly small sharks. Octopuses are very protective mothers and keep their eggs clean and safe until they are ready to hatch, at which time, she then blows the eggs out into the ocean. Sadly, once the eggs hatch, she dies. Newly hatched octopuses will eat small foods such as copepods, larval crabs, and sea stars.
No matter where you go, in every ocean around the world and on the coast of the United State you will find Octopus of one size or another. They are not fond of swimming and can generally be found in dens—small holes and crevices in rocks and coral. They are generally solitary and territorial. Octopus is one of the favorite meals of Moray eels, fish, seals, sperm whales, sea otters, and many birds of prey. They are good at hiding from predators and use several techniques to escape capture. They camouflage themselves by quickly changing their skin color, they make colorful displays or eject ink to startle or confuse potential predators, they squeeze into small crevices to escape, and they quickly propel themselves through water to get away from predators. Octopuses move using jet propulsion—they suck water into their mantle cavity, and then quickly contract their muscles to force the water out through a narrow siphon, aiming the water to steer in a particular direction.
Octopus likes to hunt at night. . All species of octopus have venom of varying levels of toxicity, which they inject using a beak that is similar to a bird. The octopus will pounce on their prey and wrapping it in the webbing between their arms. When they prey has a hard shell, they penetrate it with their beaks.
Mating among octopus is quite an unusual process compared to most mollusks. At the end of one of the arms there is a specialized tip at the end of one arm that transfers sperm to the female’s oviduct. The female sets up housekeeping in a den she has found, and lays eggs attached in chains, to the rock or coral or the den. The eggs can number in the hundreds of thousands for some species. The female guards and cares for the eggs, aerating and cleaning them until they hatch. As soon as they hatch, the young are able to swim, eat, and produce ink. The male parent dies soon after mating and the female survives only until her brood has hatched. An octopus will generally live for about one to three years, depending on the species.

It should be noted here that while they look similar, they are not the same. Octopuses and squids are both head-footed aquatic animals (cephalopods) but they differ in their physical characteristics, habitat and behavior.
The octopus head is round with a mantle along with eight arms. The arms are endowed with one or two rows of suckers, but these never have hooks or sucker rings. Squids have a triangular shaped head, a mantle and eight arms. Along with that they have two fins on their head and two tentacles. The arms of a squid are endowed with hooks and/or suckers or sucker rings. The tentacles are arranged in pairs.
According to an article in Science Friday, “Deep in the ocean’s cold, dark waters lives a species of wide-eyed octopus that will surely warm your heart with pure cuteness. Up until now, these peculiar creatures have gone unnamed. Now, scientists are preparing to formally name the species, and they’re considering the one word that captures this tiny cephalopod’s essence: Opisthoteuthis adorabilis. Researchers have been collecting and studying these unidentified cephalopods since 1990, but no one undertook the exhaustive process to scientifically identify them. Scientists need to study newly discovered creatures — inside and out — to clearly describe how they are unique from other species that may be closely related. New species identifications, including a name, are then published as articles in scientific journals.”
The Octopus has long been a favorite of science fiction writer, novels and those that would scare filmgoers.
Even poets have embraced the Octopus one of the best-known examples is by Lord Alfred Tennyson.
Octopus Poem: The Kraken.
Below the thunders of the upper deep;
Far, far beneath in the abysmal sea,
His ancient, dreamless, uninvaded sleep
The Kraken sleepeth: faintest sunlights flee
About his shadowy sides: above him swell
Huge sponges of millennial growth and height;
And far away into the sickly light,
From many a wondrous grot and secret cell
Unnumbered and enormous polypi
Winnow with giant arms the slumbering green.
There hath he lain for ages and will lie
Battening upon huge sea-worms in his sleep,
Until the latter fire shall heat the deep;
Then once by man and angels to be seen,
In roaring he shall rise and on the surface die.

“The Kraken” first appeared in Poems, Chiefly Lyrical. By Alfred Tennyson. London: Effingham Wilson, Royal Exchange, Cornhill, 1830.