Octopuses are one of the ocean’s most interesting creatures.
Everyone knows the general facts about them: they have eight arms, they are considered an incredibly intelligent animal, they have giant heads, etc.
However, there is a bit more to octopuses than you may know.
For starters there are around 300 recorded species of octopus that have been observed so far and some of them have amazing and unique abilities such as being able to produce light, mimic other ocean animals and use tools.
After a closer look, you can see just how amazing an octopus really is.
Physical Characteristics and Appearance
As a species there are about 300 recorded species of octopus that can vary in terms of psychical characteristics and appearance, however there are some features that are common among most species of octopus.
Octopuses have eight long arms that they use for locomotion, and they are invertebrates, which means they have no backbone.
In fact octopus completely lack the presence of any bones, which makes them extremely flexible and maneuverable.
Because of this octopuses are able to fit into small spaces, squeeze through tiny openings and cracks and hide in areas that would be inaccessible to most predators and vertebrae animals.
Their body is rounded and elongated, and their dark eyes are well-defined.
These large eyes allow octopuses to be able to see distinct shapes, a feat not many sea creatures possess.
The octopuses pupils are able to maintain a fixed position regardless of the octopuses physical orientation.
Octopuses can range in size anywhere from two inches to 18 feet long.
The most notable characteristic of octopuses are their strong arms which are lined with suction cups.
The eight arms come together on the octopus at the skirt, and the mouth sits in the center of the skirt.
Each of the eight arms or tentacles of an octopus generally has over 200 suction cup like protuberances that it uses to help it grab onto its prey.
These protuberances or suckers are very sensitive and capable of flexing and picking up chemical changes in the water.
The mouth has two beaks on the outside of the radula, the part of the mouth that can open shells.
In order to pump blood through their body octopuses have three hearts.
Two of the hearts are dedicated to pumping blood through its gills while one focuses on pumping blood through the rest of its body.
When observed the octopuses blood is actually blue rather than red.
This is because the octopus developed copper based blood rather than iron based blood like use humans, which helps it thrive in its underwater habitat.
Intelligence
When it comes to intelligence octopuses are one of the most intelligent invertebrates known to inhibit the ocean.
In fact over half of an octopuses neurons are in its arms (not its brain) allowing it to take in and process significant amounts of information through its tentacles.
This allows the octopus to multitask in a very effective manner.
An octopus can use some of its tentacles to try to open a shell so that it can grab its dinner while other tentacles focus on a different task.
When an octopus loses a tentacle it can regrow a new one to replace the lost tentacle, however unlike a starfish the lost tentacle does not create a new octopus.
Even when the tentacles are completely removed they may continue to act on their own, responding to their environment and attempting to feed its phantom body by reaching towards where the mouth would be if it were still attached.
These ocean animals are able to use tools, create gardens or fortresses in order to camouflage and protect themselves, use their tentacles to problem solve complex tasks, mimic other ocean animals and learn how to perform tasks by watching other more experienced octopuses.
Octopuses are also known to show different temperaments towards certain activities and objects, which suggests that these animals may have different personalities or at least preferences towards certain things.
This temperament appears to extend towards recognition as some researchers state that an octopus will modify its appearance and behavior based on who it identifies as a stranger, friendly, familiar or potentially threatening predator.
Some researchers believe that octopuses would become one of the most intelligent and dominant ocean animals alive if they had a longer lifespan (most octopuses live no longer than 3 – 5 years) as it would give them more time to develop their intelligence and improve their already impressive abilities.
Diet and Hunting Methods
Octopuses have a large variety of foods in their diet.
They mostly diet on fish, shrimp, small crabs, turtles, snails, various crustaceans and scallops, depending on which are available in their environment.
Some even eat other octopuses, but this is rare.
To catch their prey they very quickly reach for it with their arms, pull it to their beaks, and kill it by paralyzing the prey with poison that softens the meat.
Then they siphon out the meat and dine on it in hiding.
Defense/Offense Strategies
In order to capture prey and protect themselves against potential threats octopuses have an array of powerful and useful strategies that they can use.
Some of the most well known and useful strategies these ocean animals use include:
- Camouflage
- Light
- Ink
- Jet propulsion
- Mimicry
- Venom
- Tools
- Invertebrate maneuverability
- Tentacles and beak
Camouflage
Despite being colorblind these animals have an amazing ability to match their background in order to avoid detection.
When threatened or trying to hide from a predator an octopus is capable of changing its color in order to mimic its environment and blend in with its surroundings.
Camouflage can be performed so well that it can allow an octopus to imitate a wide variety of colors and patterns in its direct area resulting in an almost transparent look.
They are also capable of changing their skin texture in order to further imitate their background.
Light
Some deep sea octopuses are known to emit light throughout their body which is believed to be used to distract and disorient potential predators or hypnotize prey so that they can move in and capture it.
Ink
When camouflage doesn’t work an octopus may release a jet of dark ink like projectile in the direction of its predator.
This ink not only helps blind the potential predator but also acts as an irritant and dulls the predators sense of smell and taste making it nearly impossible to locating a fleeing octopus.
Jet propulsion
While attempting to flee a predators grasp the octopus can use jet propulsion to propel itself quickly to a safe distance in order to escape or find a new hiding place.
At top speeds it is estimated that some species of octopus can reach speeds of up to 25 mph for short bursts.
Mimicry
Mimicry works a bit differently from camouflage in that it allows the octopus to mimic the shape of other ocean animals in order to trick potential predators/prey into thinking it is a different animal species.
This is done by both camouflaging its appearance to resemble an animal and by reshaping its body by rearranging its tentacles and body shape in order to appear as a different animal.
In fact there is even an octopus named the “mimic octopus” which is capable of imitating at least 15 different animal species.
By appearing as another animal the mimic octopus can deter predators by scaring them into thinking they are the prey or that they could be harmed/poisoned by the apparent animal, such as when the octopus mimics a deadly fish.
Venom/poison
Octopuses contain venom/poison that allows them to weaken and immobilize the prey they are trying to consume.
It can also be used as a defensive measure.
The potency of the venom varies greatly from one species to the next and may also vary based on their environment and the waters temperature.
While octopuses are venomous one of the only known octopuses to be a threat to humans in regards to its venom is the blue-ringed octopus, which is significantly more dangerous than most other octopus species.
Tools
In order to protect themselves and build fortresses octopuses are known to collect tools, shells and trinkets in order to create a home for themselves and set up a fortified area.
In fact octopuses have been observed taking and carrying coconut shells around in order to use them as homes and protective barriers against potential predators.
One octopus referred to as the “blanket octopus” has even been observed ripping off the tentacles of the Portuguese man o’ war jellyfish and using it as a whip to attack other animals.
Invertebrate maneuverability
As mentioned earlier octopuses are invertebrates.
The complete lack of bones and soft bodies of these animals allows them to maneuver themselves effortlessly through tight spaces.
Octopuses have been observed squeezing through holes measuring only an inch in diameter, hiding in soda bottles and squeezing into small crevices to escape predators or enter otherwise uninhabitable spaces.
Tentacles and beak
When all else fails or when an octopus feels confident about its abilities it may decide to wrap its strong tentacles around the body of its predator/prey and squeeze the body of its victim until it breaks its spine or the victim suffocates.
It may also pull the victim in to bite it with their powerful beak.
In fact octopuses have been observed capturing and killing four foot long sharks by grabbing them with the tentacles and squeezing them to death.
Each of the 8 tentacles has over 200 suction cup like muscles that can create an air tight seal around the body of its prey making it extremely difficult if not impossible to escape the grasp of a powerful octopus.
Habitat and Migration
When people think of octopuses they generally think of the Common Octopus, a species that lives in the Atlantic Ocean and the Mediterranean Sea.
They live anywhere from 100 meters to 150 meters below the surface of the water.
Octopuses often tend to live in dens that serve as hiding places until they swim out to hunt.
Their dens are normally in rock crevices or holes they create.
They will often partially close the entrance to their den with stacked rocks to remain concealed.
The entrance of the den may be littered with shells and other trinkets that the octopus captured or fed on over the last few days/weeks.
Depending on the species some octopuses may also choose to hide in caves, sea floor holes, fortified plant vegetation and man made dens such as those created from large disposed materials or ship wrecks.
The dens are not only used for safe feeding but also provides safety from predators during rest periods and is used by female octopus as a place to safety lay their eggs while waiting for them to hatch.
While the octopuses den is a vital component to its life they are not particularly territorial and may move from one den to the next over several days or weeks and tend to remain fairly mobile.
In regards to migration it is believed that medium to large octopus may migrate vertically depending on the season.
Migration towards shallow waters tends to occur during the colder months of the year while deep sea migrations typically occur during the warmer months.
Social Structure and Communication
Octopuses tend to be solitary creatures.
They live and hunt alone, and the baby octopuses learn very little from their parents.
Male and female octopuses mate with many partners.
The mothers clean and watch their eggs vigorously until they hatch, sometimes to the point of starvation from lack of eating.
The baby octopuses leave their native environment when they mature to make a new home for themselves.
Octopuses will guard their homes aggressively.
Reproduction and Breeding
As stated above, both male and female octopuses mate with many other octopuses during their lifetime, which is only three to five years long.
Sometimes males will display a bright change in skin color to attract mates, but often octopuses do not show any mating rituals.
Male octopuses may directly make contact with the female with their sperm holding hectocotylus or break it off and give it to the female to save until she is ready to mate.
The female will lay thousands of eggs at a time and guard them carefully.
During this time the female octopus will forgo eating food in order to continually provide protection of her eggs, even at the expense of her own health and well being.
The male and female die shortly after the eggs have hatched.
Threats
The main natural predators of octopuses are sharks, seals, whales and eels.
In the larva period, they float around for a short period of time as plankton before reaching the bottom of the ocean floor, and sharks and whales eat them as plankton during this time.
Some large fish and sea turtles also eat octopuses.
Octopuses also face threats from human involvement, including habitat destruction, hunting and over-fishing.