The octopus is an eight-legged mollusk with 300 species and is classified as a Cephalopoda. It is bilaterally symmetric with two eyes on the top of its head, and a beaked mouth at the center point of its eight legs. It has a closed circulatory system keeping its blood inside the blood vessels. It has three hearts:
- Systemic – circulates blood around the body. It becomes inactive when the octopus is swimming.
- Gill – these two branchial hearts pump blood through the gills.
Its blood contains the copper-rich protein haemocyanin to transport oxygen, making the blood viscous (thick) and requires greater pressure to pump it throughout the body. This protein is why its blood is blue.
The average lifespan of an octopus is four years.
The thing we likely know best about the octopus is that when it is in danger, it shoots ink with a water jet from an ink sac under its digestive gland. The ink passes through glands that mix it with mucus so that it ends up as a dark blob surrounding it. Melanin makes the ink black.
The arms are lined with suckers (suction cups) used for gripping, manipulation, catching prey, and movement. The Giant Pacific Octopus has 280 suckers on each arm (2,240 total). Each sucker has two parts:
- Infundibulum – the fleshy, outer rim that is flexible and capable of changing shape, conforming to different surfaces.
- Acetabulum – the hollow, dome-shaped center that acts like a plunger.
Being an invertebrate (a creature without vertebrate), the octopus can deform its shape to allow it to squeeze through small spaces and gaps. If you have ever seen a video of an octopus working its way through a very small hole on a boat to get away, you would have to agree it’s a little creepy. They trail their arms behind them to propel themselves by water jet propulsion.
With thousands of “specialized cells” under its skin, the octopus is master of disguise. These cells are called chromatophores and help the octopus to change color in an instant. In addition, it has tiny areas of skin called papilli that extend or retract changing the texture of its skin to match its surroundings. The most impressive shape-shifter is the Mimic octopus. This fellow doesn’t copy its surroundings; it disguises itself as another animal, the kind predators avoid. It contorts its body, modifies its behavior, and arranges its arms in a way that allows it to impersonate a wide variety of venomous animals—lionfish, banded sole, and sea snakes to name a few. Unlike pretending to be a rock, this impersonation allows the octopus to move away from danger.
The octopus has a complex nervous system and excellent eyesight. Studies have found that they are among the most intelligent and behaviorally-diverse invertebrates.
The octopus is compared with a dog in terms of intelligence. In experiments, the octopus has solved mazes and performs tasks for food rewards. They are able to get in and out of containers. A lab had an octopus in a tank and in a separate tank other fish. The fish kept disappearing, so they installed a video camera and discovered that the octopus was escaping its tank, opening the lid of the fish tank, eating all the fish, replacing the lid, and returning to his own tank. Octopus also use tools—rocks, broken shells, broken glass, and bottle caps.
They also have the ability to recognize people. At the University of Otago in New Zealand, a captive octopus took a dislike to one of the staff. Every time she passed his tank, he squirted her with a jet of water. Seattle Aquarium biologists tested a group of octopus over a period of two weeks. One person fed the group regularly. Another touched them with a bristly brush. At the end of the test, the octopuses had determined that the one who fed them was nice and they behaved differently with that person than they did with the mean person. This proved that an octopus is capable of distinguishing between individuals, even when they wear the same clothes.
The most amazing thing about the octopus is that it has nine brains:
- Central brain – located in the frontal area of its head in a donut shape around the esophagus. This brain is responsible for sending high-level signals to the arms.
- Mini-brains – one for each of its eight arms. The arms of the octopus are directed by a mini-brain specific to it, each arm performing a different task. The arms can punch, lift, and pull up to 100 times the octopus’ own weight. They also touch, dig, and catch prey.
In a way, the octopus is like us with God. We all have our individual brains and we live according to their directions, but if we are connected to God, our “mini-brains” can follow His directions.
“Let this mind be in you which was also in Christ Jesus.” Philippians 2:5
“God permits every human being to exercise his individuality. … Those who desire to be transformed in mind and character are not to look to men, but to the divine Example. God gives the invitation, ‘Let this mind be in you, which was also in Christ Jesus.’ By conversion and transformation, men are to receive the mind of Christ. Everyone is to stand before God with an individual faith, an individual experience, knowing for himself that Christ is formed within, the hope of glory.” The Signs of the Times, September 3, 1902
Sources: nhm.ac.uk/discover/octopuses-keep-surprising-us-here-are-eight-examples-how; en.wikipedia.org/wiki/Octopus; animalsfyi.com/why-do-octopuses-have-9-brains-8-arms-3-hearts-and-blue-blood-surprising-facts; aquariumwhisperer.com/octopus-suction-cups]
Did You Know?
The octopus has feelings and can feel pain.
Pacific striped octopus use scare tactics to catch their prey. It creeps up to its prey, taps it on the shoulder causing it to jump away from the arm that touched it into the seven waiting arms.