When an octopus is scared, the octopus will often turn pale or white, which is the octopus's stress response to being surprised by a large and unfamiliar presence like someone looking into an aquarium tank or a diver.
And by turning pale and white and quickly swimming away, the octopus also tries to blend into the lighter and open water background like the sand or bright surface water.
Octopuses are also able to change color using thousands of tiny pigment containing cells that are called chromatophores and when these muscles are relaxed and the pigment sacs contract, the octopus will naturally turn pale or white.
Also octopuses only naturally see in black and white and so octopuses gauge their surroundings based on movement and brightness and if an octopus can't find a specific object to camouflage against such as a dark rock, the octopus will often default to a pale or white color, which also happens when the octopus is stressed or preparing to escape.
An octopus eats crabs, lobsters, clams, shrimp, mussels, small fish and snails and some larger species of octopuses occasionally eat sharks.
Octopuses are strictly carnivorous and hunt and eat a variety of marine life.
Octopuses pounce on their prey and wrap their prey in their webbed arms and use the suction cups to secure the prey to eat.
Then the octopus, injects a paralyzing toxin into their prey to subdue their prey and instead of teeth, octopuses use a sharp, parrot like beak to crush shells and tear flesh into bite sized pieces.
And for hard shelled mollusks, octopuses will often also drill a hole in the shell to inject the venom directly.
Octopuses can also hear, although octopuses don't have any ears.
While octopuses don't have ears, octopuses can still hear, by detecting sound vibrations using special organs that are located behind the octopuses eyes.
The special organs that octopuses have behind their eyes that allows them to detect sound vibrations are called statocysts.
The statocysts that octopuses have that allow them to detect sound vibrations are fluid filled sacs that are lined with sensory hairs that sense the movement of water particles.
Because octopuses lack traditional ears like humans and other animals, an octopuses auditory experience is different from our hearing.
An octopuses hearing is limited to lower frequencies, which often range from between 400 Hz and 1000 Hz, with the best sensitivity occurring around 600 Hz.
And instead of processing acoustic pressure waves, like humans do, octopuses instead essentially feel the acoustic particle motion and vibrations through their statocysts and bodies.
An octopuses hearing is also considered one of the octopuses weaker senses.
Although it's also believed to be vital for the octopus to detect low frequency rumbles of any approaching predators like eels, sharks and marine mammals or even for eavesdropping on nearby prey.
Octopuses can also recognize humans and individual humans.
Research also demonstrates that octopuses, which are very highly intelligent invertebrates can also tell people apart, even when the people are wearing identical clothing or uniforms.
Octopuses can also remember past interactions and sometimes even develop distinct favorites and nemeses.
Octopuses also have 2 biological sexes, which are male and female as they do reproduce sexually and distinguishing between the sexes of the octopuses comes down to looking for a single and unique reproductive organ.
Male octopuses don't have a penis, but instead male octopuses have a specialized mating arm that is called a hectocotylus, which is often located on the third right arm.
The arm lacks suction cups at the tip and is used to deliver sperm packets also known as spermatophores directly into the female octopuses mantle cavity.
Female octopuses don't have the specialized arm and all of the 8 arms of the octopus are identical.
Female octopuses also have a mantle cavity that is used for receiving the male octopuses sperm packets, which they often also store to fertilize their eggs at a later time.
In some species of octopuses, like the blanket octopus, male and female octopuses are so drastically different that they also exhibit some of the most extreme sexual dimorphism in the animal kingdom.
Female blanket octopuses can also grow up to 6 feet long and male blanket octopuses average just 1 inch long.